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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'natural'.

Category: Research article

article id 10485, category Research article
Felicia Dahlgren Lidman, Emma Holmström, Tomas Lundmark, Nils Fahlvik. (2021). Management of spontaneously regenerated mixed stands of birch and Norway spruce in Sweden. Silva Fennica vol. 55 no. 4 article id 10485. https://doi.org/10.14214/sf.10485
Highlights: The absence of forest management does not always mean economic loss; With dense spontaneous regeneration of birch and Norway spruce, the first competition release can have a high impact on future stem development; Significantly different effects on stand volume production and diameter development of Norway spruce can be expected with different biomass harvest strategies.

Timber production and profitability were evaluated for spontaneously-regenerated mixtures on two formerly clearcut areas. The abandoned areas developed into birch-dominated (Betula pendula Roth and Betula pubescens Ehrh.) stands with successional ingrowth of Norway spruce (Picea abies (L.) H. Karst.). An experiment with randomized treatments within blocks was established, using three management strategies and one unthinned control, resulting in variation in optimal rotation age, merchantable volume and species composition. The management strategies were evaluated based on total production (volume) by using measured growth data 42 years after clearcutting and the modelled future stand development. The long-term effects of spontaneous regeneration and management strategies were evaluated based on land expectation value (LEV) and compared with a fifth management strategy using artificial regeneration and intense thinnings. 12 years after treatment, at a stand age of 42 years, the unthinned control had produced the highest total stem volume. At interest rates of 2% or higher, the unmanaged forest was an economically viable strategy, even compared to an intensive management strategy with a preferred merchantable timber species. Interest rates clearly impacted the profitability of the different management strategies. This study shows that when spontaneous regeneration is successful and dense, the first competition release can have a high impact on the development of future crop trees and on the species mixture.

article id 10334, category Research article
Annija Kārkliņa, Guntis Brūmelis, Iluta Dauškane, Didzis Elferts, Lāsma Freimane, Māra Kitenberga, Zane Lībiete, Roberts Matisons, Āris Jansons. (2020). Effect of salvage-logging on post-fire tree establishment and ground cover vegetation in semi-natural hemiboreal forests. Silva Fennica vol. 54 no. 5 article id 10334. https://doi.org/10.14214/sf.10334
Highlights: Effect of salvage logging on post-fire understory vegetation was assessed; Effect of salvage logging differed depending on forest types; In dry-poor stands, Calluna vulgaris was hindering other plant species; In wet stands, logging had positive effect on understory vegetation diversity; Salvage logging enhanced the effect of natural disturbance in dry-rich stands.

Fire is a common disturbance in boreal forests causing changes in biological diversity at various spatial scales. In the past 100 years, forest management has limited fire outbreaks, but in the future, the fire-affected forest area is expected to increase in many regions due to climate change. Burned forests are typically salvage-logged, but the effect of this type of management versus natural regeneration on biological diversity is not well understood, particularly the mid-term effect to tree establishment and understory vegetation composition and diversity. Various management methods were used after a large fire in 1992 in a peatland-forest complex and neighbouring managed forests, which created an experimental setup for study of the effect of management after fire in the Sliteres National park, northwestern Latvia. Understory vegetation was described in plots using a design of four forest and three management types: natural regeneration (unmanaged) and managed sites with salvage logging followed by no further human intervention and salvage logging with planting. Post-fire management had different effect in each forest type. Species richness was higher in forest types with salvage logging than in natural regenerated sites on rich wet and rich dry forest types, but not for the poor forest types. Tree regeneration was generally greater in salvage-logged stands, but differed between forest types. Species composition was related to tree regeneration and canopy openness. In contrast to other studies, salvage logging had a positive mid-term effect to ground vegetation diversity and tree establishment in the studied stands, implying potential for concomitant management and conservation of ground cover vegetation in semi-natural stands.

  • Kārkliņa, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: annija.karklina@silava.lv (email)
  • Brūmelis, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia ORCID ID:E-mail: guntis.brumelis@lu.lv
  • Dauškane, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia ORCID ID:E-mail: iluta.dauskane@lu.lv
  • Elferts, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia; University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia ORCID ID:E-mail: didzis.elferts@lu.lv
  • Freimane, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: lasma.freimane@silava.lv
  • Kitenberga, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: mara.kitenberga@silava.lv
  • Lībiete, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: zane.libiete@silava.lv
  • Matisons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: robism@inbox.lv
  • Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia ORCID ID:E-mail: aris.jansons@silava.lv
article id 10002, category Research article
Bayasaa Tumenjargal, Futoshi Ishiguri, Haruna Aiso-Sanada, Yusuke Takahashi, Bayartsetseg Baasan, Ganbaatar Chultem, Jyunichi Ohshima, Shinso Yokota. (2018). Geographic variations of wood properties of Larix sibirica naturally grown in Mongolia. Silva Fennica vol. 52 no. 4 article id 10002. https://doi.org/10.14214/sf.10002
Highlights: Significant differences (p  < 0.01) among five stands were found in tree height, stress-wave velocity of stems, dynamic Young’s modulus of stems and logs, annual ring width, and latewood percentage, suggesting that there was geographic variation of mechanical properties of wood in Larix sibirica (Münchh.) Ledeb. grown in Mongolia; Dynamic Young’s modulus of logs in L. sibirica trees can be predicted by stress-wave velocity of stems; Stem diameter of L. sibirica naturally grown in Mongolia is closely related to radial growth at initial stage of growth, especially within the first twenty years.

Geographic variations in growth, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density were investigated for Larix sibirica (Münchh.) Ledeb. naturally grown in Mongolia. A total of 250 trees with 20 to 30 cm in stem diameter at a height of 1.3 m above ground level were selected from each natural stand in five different provenances in Mongolia. In addition, five trees in each stand were cut for measuring dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density. Mean values of stress-wave velocity of stems in each stand ranged from 2.92 to 3.41 km s–1, and the mean value of five stands was 3.23 km s–1. Mean values of dynamic Young’s modulus of logs in each stand ranged from 5.17 to 9.72 GPa. A significant correlation (r = 0.798, p < 0.01) was found between stress-wave velocity of stems and dynamic Young’s modulus of logs. Among the five stands, the highest and the lowest values of average annual ring number were 193 and 44, respectively. Mean values of basic density in five trees within each stand were examined and ranged from 0.52 to 0.56 g cm–3. Significant differences among five stands were found in tree height, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width and latewood percentage, suggesting that L. sibirica trees naturally grown in Mongolia have geographic variations in mechanical properties of wood.

  • Tumenjargal, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia ORCID ID:E-mail: t_bayasaa88@yahoo.com
  • Ishiguri, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan ORCID ID:E-mail: ishiguri@cc.utsunomiya-u.ac.jp (email)
  • Aiso-Sanada, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan ORCID ID:E-mail: haiso@ffpri.affrc.go.jp
  • Takahashi, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan ORCID ID:E-mail: zo.r.by0814@gmail.com
  • Baasan, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia ORCID ID:E-mail: bayartsetseg@must.edu.mn
  • Chultem, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia ORCID ID:E-mail: ganbaatar_ch@must.edu.mn
  • Ohshima, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan ORCID ID:E-mail: joshima@cc.utsunomiya-u.ac.jp
  • Yokota, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan ORCID ID:E-mail: yokotas@cc.utsunomiya-u.ac.jp
article id 1663, category Research article
Marta Kempf, Monika Konnert. (2016). Distribution of genetic diversity in Fagus sylvatica at the north-eastern edge of the natural range. Silva Fennica vol. 50 no. 4 article id 1663. https://doi.org/10.14214/sf.1663
Highlights: European beech at the north-eastern edge of its natural range in Poland have a high level of genetic variation, similar to the populations from Central Europe; The differences between the beech provenances from the two centres in Poland, which were previously identified on the basis of pollen analyses and phenotypic traits, have now been genetically confirmed.

An understanding of the genetic variation of the beech, especially at the edge of its natural distribution, is essential because of the change in natural distribution of the species resulting from changing climatic conditions. The main aim of the study was to determine the level of genetic diversity of European beech at the north-eastern edge of its natural range. The other aim was to check the genetic variation of beech from the two centres, the north and the south of Poland, which were identified in previous findings based on pollen analyses and phenotypic traits. The research material was the progeny of twelve beech provenances. The genetic structure of the populations was determined by ten highly variable microsatellite DNA loci. The results confirmed the high genetic diversity of beech at the north-eastern edge of its natural distribution, which infers the probability of their good adaptation to the changing climate and an extension of the range. Genetic analyses confirmed the existence of two genetic centres for beech in Poland. The populations from south-eastern Poland had a slightly higher diversity than the populations from the north-western area, which may indicate that the colonisation of Poland occurred by two routes. The results are important for creating the borders of the provenance regions and for limiting the transfer of seeds and seedlings. The choice of forest reproductive material, based on the knowledge of genetic diversity, is very important for the stability of future forests.

  • Kempf, Department of Genetics and Forest Tree Breeding, Faculty of Forestry, University of Agriculture in Krakow, Al. 29-listopada 46, 31–425 Krakow ORCID ID:E-mail: m.kempf@ur.krakow.pl (email)
  • Konnert, Bavarian Office for Forest Seeding and Planting, Forstamtsplatz 1, 83317 Teisendorf, Germany ORCID ID:E-mail: monika.konnert@asp.bayern.de
article id 1564, category Research article
Stanislav Vacek, Zdeněk Vacek, Lukáš Bílek, Jaroslav Simon, Jiří Remeš, Iva Hůnová, Jan Král, Tereza Putalová, Miroslav Mikeska. (2016). Structure, regeneration and growth of Scots pine (Pinus sylvestris L.) stands with respect to changing climate and environmental pollution. Silva Fennica vol. 50 no. 4 article id 1564. https://doi.org/10.14214/sf.1564
Highlights: Pine forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics; Tree-ring width was positively correlated with precipitation, while it was negatively correlated with temperature in growing seasons; Mean NOx concentrations showed positive effect on radial growth of pine; Serious defoliation was caused by SO2 concentrations and N deposition in combination with extreme climate events.

Changes in the structure and development of managed Scots pine (Pinus sylvestris L.) stands with respect to changing environmental conditions were set for the period 1979–2015. The study was conducted in conditions of natural pinewoods and pine-oak sites on five permanent research plots (0.25 ha) in Eastern Bohemia, Czech Republic (CR). Studied forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics. The standing volume of regularly distributed tree layer in 2015 was in the range of 320–434 m3 ha–1, which indicates an increase by 5.9–20.0% over 10 years. Correlation between pine radial increment and the amount of precipitation was generally the strongest one. Positive statistically significant correlation between diameter increment and temperature was demonstrated only for the average March temperature of the current year. Within the CR, study site can be characterised as a medium polluted area both for sulphur and nitrogen, despite this SO2 concentrations and N deposition in combination with extreme climate events caused severe defoliation in pine stands. Conversely, radial growth was positively significantly correlated with mean NOx concentrations. Drought mainly in combination with even medium environmental pollution can further worsen the health status of pine stands in lowland areas of Central Europe. Thus, formulation of silvicultural techniques able to mitigate the impact of these stress factors is needed.

  • Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: vacekstanislav@fld.czu.cz
  • Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: vacekz@fld.czu.cz
  • Bílek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: bilek@fld.czu.cz
  • Simon, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, 613 00 Brno, Czech Republic ORCID ID:E-mail: jaroslav.simon@mendelu.cz
  • Remeš, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: remesj@email.cz (email)
  • Hůnová, Czech Hydrometeorological Institute, Na Šabatce 17 143 06 Prague, Czech Republic ORCID ID:E-mail: hunova@chmi.cz
  • Král, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: kraljan@fld.czu.cz
  • Putalová, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic ORCID ID:E-mail: putalova@fld.czu.cz
  • Mikeska, University of Hradec Králové, Faculty of Science, Rokitanského 62, 500 03 Hradec Králové, Czech Republic ORCID ID:E-mail: Mikeska.Miroslav@uhul.cz
article id 1279, category Research article
Andreas Kreutz, Tuomas Aakala, Russell Grenfell, Timo Kuuluvainen. (2015). Spatial tree community structure in three stands across a forest succession gradient in northern boreal Fennoscandia. Silva Fennica vol. 49 no. 2 article id 1279. https://doi.org/10.14214/sf.1279
Highlights: We studied the tree community spatial structure in three 1.2-ha plots representing naturally developed northern boreal forests of varying ages; Spatial structure showed little differences between the mid-successional, late-successional and old-growth stands; The occurrence of Picea abies relative to Betula spp. indicated a mosaic-like spatial assembly; Mosaics are likely maintained by species-specific replacement, not reciprocal replacement as thought earlier.
Development of species composition during succession is well studied in natural boreal forests, but empirical assessments of how within-stand spatial structure develops in late-successional stages are few. Here, we quantified spatial patterns in three unmanaged stands consisting of Picea abies (L.) Karst. and Betula pubescens Ehrh. and Betula pendula Roth (hereafter Betula spp.) in northern boreal Fennoscandia. We conducted a comprehensive analysis of small-scale spatial point patterns in three fully mapped 1.2-ha sample plots, representing different forest developmental stages: mid-successional, late-successional and old-growth forest. We used several variants of Ripley’s K-function to analyze the spatial point patterns along the successional gradient. Univariate analyses showed that mature trees of both species were either randomly distributed or clumped. P. abies saplings were clumped, and Betula spp. saplings occurred in a random or clumped manner. In the bivariate analyses, saplings were more likely to be found in the surroundings of mature trees of the same species, but occurred independent of the individuals of other tree species. Mature trees showed interspecific repulsion. Only modest differences occurred in the univariate patterns between the three successional stages, but in the bivariate analyses the most evident patterns, i.e. intraspecific attraction and interspecific repulsion, were stronger in the older successional stages. Overall, the studied stands appear structured as species-specific mosaics. These mosaics, along with mixed species composition, seem to be maintained by species self-replacement, which contrasts with findings from earlier studies.
  • Kreutz, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: andreas.kreutz@wald-rpl.de
  • Aakala, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID: http://orcid.org/0000-0003-0160-6410 E-mail: tuomas.aakala@helsinki.fi (email)
  • Grenfell, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: russell.grenfell@gmail.com
  • Kuuluvainen, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: timo.kuuluvainen@helsinki.fi
article id 920, category Research article
Hannu Hökkä, Jaakko Repola, Mikko Moilanen, Markku Saarinen. (2012). Seedling establishment on small cutting areas with or without site preparation in a drained spruce mire – a case study in northern Finland. Silva Fennica vol. 46 no. 5 article id 920. https://doi.org/10.14214/sf.920
A large proportion of drained spruce mire stands is currently approaching regeneration maturity in Finland. We studied the effect of cutting – small canopy openings (78, 177, and 314 m2) and small clear-cuts (0.25–0.37 ha) – with or without site preparation (scalping) on the establishment of natural Norway spruce seedlings in one experimental drained spruce mire stand in northern Finland. The cuttings were made in winter 2004–2005 and site preparation with scalping in early June 2005. The experimental design was composed of four blocks with altogether four clear-cuts and 33 canopy openings. The seedling establishment was surveyed annually (2006, 2008–2010) from five circular sample plots (one 10 m2 and four 5 m2 plots in size) located within the canopy openings and from 18 circular 5 m2 sample plots systematically located in the scalped and untreated halves of the clear-cuts. Site preparation was found unnecessary, because it resulted in a clearly lower number of seedlings in the openings. A slight negative effect was also found in the clear-cuts. In the two years following the cuttings, the number of seedlings increased quickly in the canopy openings, but more gradually in the clear-cut areas. In 2010, on average 15 500 new seedlings were observed in the canopy openings and 6700 in the clear-cut areas, of which 5050 and 1200, respectively, were >0.1 m tall spruces. The proportion of birch increased in the last two years, being ca. 22% in the openings and 45% in the clear-cuts in 2010. The spatial distribution of seedlings was more uneven in the clear-cuts than in the openings, with 41% and 20% of survey plots empty, respectively.
  • Hökkä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: hannu.hokka@metla.fi (email)
  • Repola, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: jaakko.repola@metla.fi
  • Moilanen, Finnish Forest Research Institute, Oulu Unit, P.O. Box 413, FI-90014 University of Oulu, Finland ORCID ID:E-mail: mikko.moilanen@metla.fi
  • Saarinen, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: markku.saarinen@metla.fi
article id 910, category Research article
Gernot Erber, Christian Kanzian, Karl Stampfer. (2012). Predicting moisture content in a pine logwood pile for energy purposes. Silva Fennica vol. 46 no. 4 article id 910. https://doi.org/10.14214/sf.910
Determining the moisture content of naturally dried fuel stock without frequent measuring is a problem still unsolved. Modelling moisture content based on automatically captured meteorological data could provide a solution. An accurate model would allow the drying period and the point of chipping to be optimised. For the experimental study, a metal frame supported by load sensors and loaded with 17 tons of logwood was set up next to a meteorological station. A multiple linear regression model was used to link meteorological and load data to provide a formula for determining the moisture content. The pile dried for a period of 14 months (average temperature of 7.3 °C, a humidity of 81%, and 777 mm of rainfall). The overall moisture content dropped from 50.1% to 32.2%. The regression model, which based on daily means and sums of meteorological parameters, provided a mean deviance from the observed curve of –0.51%±0.71% within the period of investigation. Relative humidity was found to be most important parameter in drying. Increased moisture content resulting from rainfall greater than 30 mm per day reverted back to pre-rainfall values within two to three days, if no other rainfall events followed. Covering the pile would have a positive effect on the drying performance. In terms of economic benefit it could be shown that natural drying is beneficial. Overall this study shows that meteorological data used in site specific drying models can adequately predict the moisture content of naturally dried logwood.
  • Erber, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: gernot.erber@boku.ac.at (email)
  • Kanzian, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: christian.kanzian@boku.ac.at
  • Stampfer, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: karl.stampfer@boku.ac.at
article id 89, category Research article
Russell Grenfell, Tuomas Aakala, Timo Kuuluvainen. (2011). Microsite occupancy and the spatial structure of understorey regeneration in three late-successional Norway spruce forests in northern Europe. Silva Fennica vol. 45 no. 5 article id 89. https://doi.org/10.14214/sf.89
We compared microsite occupancy and three spatial structure of regeneration in three primeval late-successional Norway spruce dominated forests. One area lay in the middle boreal zone in Russia (Dvina-Pinega) where larger-scale disturbance from bark beetles and drought had occurred; the other areas lay in the northern boreal zone, one in Finland (Pallas-Ylläs) had encountered only small-scale disturbance, and one in Russia (Kazkim) had been influenced by fire. We mapped all spruce (Picea abies) and birch (Betula pendula and Betula pubescens) trees with diameter at breast height (DBH) ≥ 10 cm on 40 m 400 m plots, and those with DBH < 10 cm on 2 m or 4 m 400 m subplots. On the subplots we also recorded microsite occupancy and estimated microsite availability. At all study areas small seedlings (h < 0.3 m) of both spruce and birch were found largely on disturbance-related microsites. Birch saplings (h ≥ 1.3 m, DBH < 10 cm) disproportionately occupied deadwood-related microsites at Dvina-Pinega. In contrast, spruce saplings at all study areas, and birch saplings at Kazkim and Pallas-Ylläs, showed less, or no, preference. Our results thus confirm the importance of disturbance-related microsites for regeneration establishment, but not necessarily for long-term survival. No spatial segregation between the overstorey (DBH ≥ 10 cm) and saplings (h ≥ 1.3 m, DBH < 10 cm) or seedlings (h < 1.3 m) was found at Pallas-Ylläs or Kazkim, and only three instances of very weak segregation were found at Dvina-Pinega. This suggests that the regeneration gap concept may not be useful for describing the regeneration dynamics of primeval boreal forests.
  • Grenfell, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland ORCID ID:E-mail: russell.grenfell@helsinki.fi (email)
  • Aakala, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland ORCID ID:E-mail:
  • Kuuluvainen, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland ORCID ID:E-mail:
article id 87, category Research article
Radek Bace, Miroslav Svoboda, Pavel Janda. (2011). Density and height structure of seedlings in subalpine spruce forests of Central Europe: logs vs. stumps as a favourable substrate. Silva Fennica vol. 45 no. 5 article id 87. https://doi.org/10.14214/sf.87
Decaying logs and stumps provide an important seedling substrate in natural subalpine forests. However, only stumps present such a role in managed forests. The aim of this study was to assess the differences in the process of seedling colonization between logs and stumps. The study was carried out in the Czech Republic, in two old-growth subalpine spruce forests located in the Bohemian Forest and Ash Mts., dominated by Athyrium distentifolium Opiz and Vaccinium myrtillus L. undergrowth, respectively. Norway spruce (Picea abies (L.) Karst.) regeneration growing on logs, stumps and non-coarse woody debris (CWD) microsites was surveyed. Regeneration (height 0–2.0 m) densities exceeded 5000 individuals per ha on both sites. The average density of P. abies regeneration per square meter of substrate was 0.3-5.7-19.6 and 0.5-3.8-11.0 on non-CWD microsites, logs and stumps, located in A. distentifolium and V. myrtillus undergrowth, respectively. Stumps and non-CWD microsites dominated by V. myrtillus, supported a higher proportion of taller seedlings per plot compared to the small seedlings growing on logs and non-CWD dominated by A. distentifolium ground-cover. The disproportion in regeneration densities between the stumps and the original logs decreased with increasing stages of decay. The tallest regeneration growing on stumps (root-soil plates) was significantly older than that growing on the logs (stems). Based on these two latter findings, the stumps appeared to provide suitable seedling substrates several years earlier than the logs did. Therefore, we conclude that the stumps play a more important role (relative to their covered area, 21–28 m2 ha–1) in terms of suitable microsites for regeneration, than the logs do.
  • Bace, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic ORCID ID:E-mail: bace@fld.czu.cz (email)
  • Svoboda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic ORCID ID:E-mail:
  • Janda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic ORCID ID:E-mail:
article id 97, category Research article
Hannu Hökkä, Jaakko Repola, Mikko Moilanen, Markku Saarinen. (2011). Seedling survival and establishment in small canopy openings in drained spruce mires in Northern Finland. Silva Fennica vol. 45 no. 4 article id 97. https://doi.org/10.14214/sf.97
A large proportion of drained spruce mire stands is currently approaching regeneration maturity in Finland. Traditional regeneration methods with effective site preparation and planting generally result in satisfactory seedling stands also in spruce mires. However, natural regeneration methods may be more appropriate in protecting watercourses and minimizing regeneration costs. We studied the survival of advance growth and establishment of new seedlings in small canopy openings that were cut at three different diameters in two experimental drained spruce mire stands in Northern Finland (Tervola and Oulu) in 2004. The number of seedlings was repeatedly surveyed from five small circular plots (one 10 m2 and four 5 m2 plots in size) located within the opening. Advance growth which survived the cutting and new seedlings were separated in the surveys. The density of advance growth was on average 9000 ha–1 after cutting, and it decreased by 30% during the five-year monitoring period (2006–2010) due to natural mortality. The number of new seedlings increased rapidly within the three years after cutting the openings. In 2010, 11 000–26 000 new seedlings ha–1 in Tervola and 12 000–16 000 ha–1 in Oulu on average were observed. The size of the opening had no clear effect on the regeneration result. The proportion of birch of the new seedlings increased with time and opening size in Tervola. The results show that Norway spruce regenerates naturally in small canopy openings cut in mature drained spruce mire stands.
  • Hökkä, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: hannu.hokka@metla.fi (email)
  • Repola, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland ORCID ID:E-mail:
  • Moilanen, Finnish Forest Research Institute, Muhos Research Unit, Muhos, Finland ORCID ID:E-mail:
  • Saarinen, Finnish Forest Research Institute, Parkano Research Unit, Parkano, Finland ORCID ID:E-mail:
article id 96, category Research article
Scott R. Abella. (2011). How well do U.S. Forest Service terrestrial ecosystem surveys correspond with measured vegetation properties? Silva Fennica vol. 45 no. 4 article id 96. https://doi.org/10.14214/sf.96
Reliable estimates of species composition that forest sites are capable of supporting – specific to ecosystem mapping units across landscapes – are useful for many purposes in forest science and management. Like forestry agencies in numerous countries, the U.S. Forest Service has invested in ecological land classification (termed terrestrial ecosystem survey [TES] in the study region of Arizona) that includes ecosystem-explicit species lists taken to be estimated potential natural vegetation (PNV). Using multivariate community analyses, PNV in the TES was compared to measured species composition on 66 sites representing among the least-disturbed vegetation (considered this study’s measured PNV) spanning 11 ecosystem types on a Pinus ponderosa P. & C. Lawson landscape in northern Arizona, USA. Agreement between the TES PNV and measured species composition was lowest for forbs and shrubs (compared to graminoids), and species composition differed significantly between the TES and this study for at least one plant lifeform in 73% of ecosystems. Reasons for differences between the TES and this study are difficult to resolve, but in some cases appear to result from identification of different species pools in the region. This study suggests that the TES is a useful starting point in understanding vegetation-environment relationships, but further work is needed to refine species lists and more thoroughly account for the influences of fire, grazing, and climate that can influence both PNV and current vegetation. Refining and updating ecosystem-specific species lists may benefit existing forest site classifications and could be planned for when new site classifications are developed, especially with changing climates.
  • Abella, Department of Environmental and Occupational Health, University of Nevada Las Vegas, Las Vegas, Nevada 89154-3064 USA ORCID ID:E-mail: scott.abella@unlv.edu (email)
article id 172, category Research article
Guntis Brumelis, Maris Strazds, Zanna Eglava. (2009). Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia. Silva Fennica vol. 43 no. 5 article id 172. https://doi.org/10.14214/sf.172
We examined the regeneration patterns of Pinus sylvestris L. in a natural treed mire in the hemiboreal zone in Latvia. Data on tree stem age and size was collected in 207 fine-scale plots (10 m2) and 4 medium-scale plots (400 m2). Size structure of living and dead trees was also estimated on transects 180-m and 250-m length and 10-m width. In addition, the vegetation was described in 1-m2 plots to determine preferred microsites for P. sylvestris establishment. Pinus sylvestris showed continuous regeneration by an inverse J-shaped age and size structure. Pulses of mortality induced by fire were also evident. Regeneration of P. sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free of competition from Ledum palustre L. and graminoids, which were found in small interspersed patches throughout the mire. The spatial pattern of tree cohorts differed, probably due to changing moisture conditions altering seedbed conditions and by fire-induced mortality in specific areas. Recent rapid invasion by Betula pubescens Ehrh. and Picea abies (L.) Karst. in a post-fire period since 1971 is probably associated with drier conditions.
  • Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia ORCID ID:E-mail: guntis.brumelis@lu.lv (email)
  • Strazds, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia ORCID ID:E-mail:
  • Eglava, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia ORCID ID:E-mail:
article id 295, category Research article
Pekka Kaitaniemi, Janne Riihimäki, Julia Koricheva, Harri Vehviläinen. (2007). Experimental evidence for associational resistance against the European pine sawfly in mixed tree stands. Silva Fennica vol. 41 no. 2 article id 295. https://doi.org/10.14214/sf.295
This study examined whether the saplings of Scots pine (Pinus sylvestris) exhibit associational resistance against the European pine sawfly Neodiprion sertifer (Hymenoptera, Diprionidae) when grown in a mixture with 50% silver birch (Betula pendula). The number of sawflies on pine trees in pure and mixed stands was manipulated at two experimental sites during two years. Survival of larvae and eggs was monitored, and the numbers of presumed sawfly predators were counted. A lower proportion of sawfly larvae and eggs survived on pines grown in the mixture with birch as compared with pure pine stands. Lower survival of sawfly larvae in the mixed stands was associated with the higher abundance of ants in these stands. The numbers of other sawfly predators (e.g. spiders and predatory heteropterans) differed between the study sites and were negatively associated with the presence of ants, which suggests possible interference between these groups. Although sawfly survival was lower on pines in the mixed stands, providing evidence of associational resistance, a related study shows the same trees had a higher number of ant-tended aphid colonies as compared with pines in the pure stands. Therefore, instead of considering resistance against individual herbivore species, it seems more practical to use associational resistance as a trait representing the resistance of larger systems, such as whole tree stands, against the total damage caused by herbivores in general.
  • Kaitaniemi, Hyytiälä Forestry Field Station, University of Helsinki, Hyytiäläntie 124, FI-35500 Korkeakoski, Finland ORCID ID:E-mail:
  • Riihimäki, Section of Ecology, Department of Biology, University of Turku, FI-20014 Turku, Finland ORCID ID:E-mail:
  • Koricheva, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK ORCID ID:E-mail:
  • Vehviläinen, Section of Ecology, Department of Biology, University of Turku, FI-20014 Turku, Finland ORCID ID:E-mail:
article id 308, category Research article
Ville Hallikainen, Mikko Hyppönen, Juha Hyvönen, Juhani Niemelä. (2007). Establishment and height development of harvested and naturally regenerated Scots pine near the timberline in North-East Finnish Lapland. Silva Fennica vol. 41 no. 1 article id 308. https://doi.org/10.14214/sf.308
Researchers and professionals in practical forestry have faced problems concerning the regeneration success of Scots pine in natural regeneration near the timberline in North-East Lapland. The aim of the study was to analyze the seedling establishment and seedling height development of Scots pine in seed-tree stands in the area. The average number of living pine seedlings in the study stands was about 1000 ha–1, but there was considerable variation between the stands. The seedling density was modelled using a multinomial logistic regression with a random factor. Forest site type and the time since seed-tree cutting were the most significant explanatory variables in the model. The probability of reaching the acceptable seedling density was higher on dry site types than on the more fertile ones. The probability increased with the time elapsed since the regeneration activities. Effective temperature sum and the number of intermediate pines also positively affected the probability, but the presence of residual trees negatively. On northern and eastern slopes the probability was lower than on southern and western ones. Seedling height was modelled using a linear mixed model. The age of a dominant seedling was the most positively effective explanatory variable in the height development model. Other positively affecting significant predictors were time since seed-tree cutting, number of intermediate birches, and distance between a seedling and the nearest seed tree. Degree of paludification had a negative effect. The study suggests that the regeneration of Scots pine in North-East Lapland is a relatively slow process.
  • Hallikainen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: ville.hallikainen@metla.fi (email)
  • Hyppönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: mikko.hypponen@metla.fi
  • Hyvönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: juha.hyvonen@metla.fi
  • Niemelä, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID:E-mail:
article id 314, category Research article
Yuhua Wang, Helena Korpelainen, Chunyang Li. (2006). Microsatellite polymorphism in the edaphic spruce, Picea asperata, originating from the mountains of China. Silva Fennica vol. 40 no. 4 article id 314. https://doi.org/10.14214/sf.314
Microsatellite variation of Picea asperata Mast. originating from the mountains of China was investigated by analyzing variation at seven SSR loci in 250 individuals representing ten populations. A fair degree of genetic diversity and considerable population subdivision occurred with the mean gene diversity (H) of 0.707, and genetic distances among populations varying between 0.121 and 0.224 (FST) and between 0.100 and 0.537 (RST). However, inter-population genetic distances showed no correlation with geographic distances between the population sites. This ruled out a simple isolation by distance model and suggested that migration does not have a great impact. In fact, the amount of gene flow, detected using private alleles, was very low, equaling only 0.753. Allele permutation tests revealed that stepwise-like mutations, coupled with genetic drift, could contribute to population differentiation. Moreover, significant genetic differences between populations were detected at most loci. The results indicate that natural selection, presumably through environmental stress, may be one of the main factors causing micro-geographical differentiation in the genetic structure of P. asperata. Based on SSR genotypes, 70% of the 250 individuals were correctly classified into their sites of origin. This suggests that microsatellites (SSRs) are effective in distinguishing genotypes of P. asperata originating from diverse eco-geographical sites in China.
  • Wang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, China ORCID ID:E-mail:
  • Korpelainen, Department of Applied Biology, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail:
  • Li, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China ORCID ID:E-mail: licy@cib.ac.cn (email)
article id 479, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Ivar Gjerde, Vegard S. Gundersen. (2005). Historical logging, productivity, and structural characteristics of boreal coniferous forests in Norway. Silva Fennica vol. 39 no. 3 article id 479. https://doi.org/10.14214/sf.479
Conservation of forest biodiversity has brought about an interest in evaluating the naturalness of forests, and to locate and protect semi-natural and old-growth forests in the Fennoscandian countries. However, it is not always clear how natural these forests really are, and how the past management history has affected their present structural composition. We studied the relationships between cut stumps from historical logging activity (50–100 years ago) and forest structural characteristics of today in a total of 385 0.25 ha plots in three boreal coniferous forests which are parts of National Nature Reserves in Norway. We also studied how forest productivity influenced these relationships. In plots with negligible logging impact we found the amount of living trees, dead wood, and size of the oldest trees mainly to increase with increasing productivity, whereas the age of the oldest trees decreased. The amount of deciduous trees was generally low irrespective of productivity. The intensity of logging did not consistently influence most of these forest structural variables, neither at low- nor at high-productive sites. The only consistent relationship in all study areas was a decreasing amount of dead wood with increasing logging intensity at high-productive sites. Also, the decay class distribution of dead wood was more right-skewed (indicating on-going accumulation of dead wood) the more logging had occurred at high-productive sites. Except from the effects on dead wood, previous logging does not show up as a major determinant of other stand structures of today.
  • Storaunet, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway ORCID ID:E-mail: ken.storaunet@skogforsk.no (email)
  • Rolstad, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway ORCID ID:E-mail:
  • Gjerde, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway ORCID ID:E-mail:
  • Gundersen, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway ORCID ID:E-mail:
article id 410, category Research article
Jouni Siipilehto, Juha Siitonen. (2004). Degree of previous cutting in explaining the differences in diameter distributions between mature managed and natural Norway spruce forests. Silva Fennica vol. 38 no. 4 article id 410. https://doi.org/10.14214/sf.410
The degree of naturalness was assessed in 37 mature (stand age 80 198 yrs) Norway spruce dominated stands located in southern Finland by measuring the number (0 610 ha–1) and basal area (0 33 m2 ha–1) of cut stumps. The Johnson’s SB distribution was fitted for living spruce trees to describe the dbh-frequency and basal area-dbh distributions. Regression models were constructed for predicting the parameters of the SB distribution using traditional stand parameters (median diameter, basal area, stem number) and the cut stump variables (number, basal area). Stump variables improved the models and enabled to explain the differences in diameter distributions between stands with varying intensity of past cutting. Model for basal area-dbh distribution was more accurate than dbh-frequency model in terms of regression statistics, but less accurate in terms of generated stand variables. The number and basal area of cut stumps seem to be useful and simple measures of stand naturalness which have potential uses in stand modelling and biodiversity-oriented forestry planning.
  • Siipilehto, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: jouni.siipilehto@metla.fi (email)
  • Siitonen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: juha.siitonen@metla.fi
article id 434, category Research article
Igor Drobyshev, Mats Niklasson, Per Angelstam. (2004). Contrasting tree-ring data with fire record in a pine-dominated landscape in the Komi Republic (Eastern European Russia): recovering a common climate signal. Silva Fennica vol. 38 no. 1 article id 434. https://doi.org/10.14214/sf.434
For the period 1420–1960 we contrasted fire events reconstructed at 14 sites distributed over a 50 km x 50 km area in the central part of the Komi Republic (European Russia) with a set of tree-ring width chronologies of Scots pine (Pinus sylvestris L.), developed for the same area. Our aim was to infer common climatic information contained in tree-ring variables and independently dated fire events with the help of a superposed epoch analysis. The strongest weather–growth link was shown for the latewood width, which was positively correlated with the temperature in April–May and July–August of the current growth season and with previous year precipitation in July–August. Earlywood width was positively affected by previous year precipitation in May and November. The relationship between yearly ring variables and multiple-site fire events was dependent on the seasonal timing of fire events as recorded in the scars. In years with early-season fires (which made up 37% of all fires dated with seasonal resolution) total ring width was significantly narrower. In years with late-season fires (63%) total ring width, earlywood, and latewood width were significantly wider. Years with late-season fires tended to be associated with local highs of the latewood width chronologies over 1400–1960, which implied a link between decadal-scale climate variation and fire regime of the area.
  • Drobyshev, SUFOR Project, Department of Plant Ecology and Systematics, Ecology Building, Sölvegatan 37, Lund University, SE-223 62 Lund, Sweden ORCID ID:E-mail: igor.drobyshev@ekol.lu.se (email)
  • Niklasson, SUFOR Project, Southern Swedish Forest Research Centre, SLU, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Angelstam, Grimsö Wildlife Research Station, Department of Conservation Biology, Forest Faculty, SLU, SE-730 91 Riddarhyttan, Sweden ORCID ID:E-mail:
article id 518, category Research article
Mats Hannerz, Curt Almqvist, Roland Hörnfeldt. (2002). Timing of seed dispersal in Pinus sylvestris stands in central Sweden. Silva Fennica vol. 36 no. 4 article id 518. https://doi.org/10.14214/sf.518
The objective of the study presented here was to describe the variation in timing of seed dispersal from Scots pine (Pinus sylvestris L.) seed trees in central Sweden. Seeds were collected in traps at two sites, for three years at one, and four years at the other . The traps were emptied from March to August each year at 1–2 week intervals during the main period of seed dispersal. The annual seed fall varied between 200 000 and 1.6 million seeds per hectare. The seed fall started in mid to late April, shortly after the heat sum had started to accumulate. The most intensive seed fall took place in early to mid May. The peak period, when 50% of the total seed dispersal occurred, lasted for 18–28 days at the different sites and years. The variation in timing among years seemed to be mainly due to climatic factors – high temperatures promoted seed dispersal, for instance. The results may be useful for planning the time of scarification to optimise the natural regeneration of Scots pine. The data suggest that scarification in the spring, no later than mid-May, would generally create a good seed-bed for most of the current year’s seeds, whereas scarification in late May or June would bury a large proportion of this cohort.
  • Hannerz, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: mats.hannerz@skogforsk.se (email)
  • Almqvist, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Hörnfeldt, Swedish University of Agricultural Sciences, Dept. of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden ORCID ID:E-mail:
article id 564, category Research article
Brett G. Purdy, S. Ellen Macdonald, Mark R. T. Dale. (2002). The regeneration niche of white spruce following fire in the mixedwood boreal forest. Silva Fennica vol. 36 no. 1 article id 564. https://doi.org/10.14214/sf.564
Early establishment of white spruce (Picea glauca) in mixedwood boreal forest stands following fire was examined at several times-since-fire (1-, 2-, 4-, 6-, 14-years). Abiotic and biotic conditions in the stands were assessed at two scales, tree plot (5 m x 5 m) and microsite (1 m x 1 m), along with presence, density and height of white spruce seedlings. Germination and survival of seed sown 1- and 4-years post fire were quantified. Survival and growth of nursery-grown seedlings, and mycorrhizal colonization, survival and growth of sterile seedlings, planted 1-year post-fire were assessed. At the tree plot scale, presence of white spruce seedlings 1-year post-fire could be reliably predicted by organic layer depth and distance to and strength of seed source. In contrast, none of the biotic or abiotic factors measured was strongly correlated with occurrence or density of white spruce seedlings 6- and 14- years post-fire. At the microsite scale, seedling recruitment immediately post-fire was limited to a distinct subset of available microsites (greater % cover of downed wood and moss, lower % cover of litter and herbaceous vegetation). Likewise, seedling occurrence in older burns was associated with distinct microsite conditions; although this was more likely an effect of white spruce presence, rather than the cause. Less than 3% of seed sown 1 yr post-fire survived to become 1yr old germinants, survival was 41% over the next three years. Availability of suitable regeneration microsites declines rapidly with time-since-fire; less than 0.3% of seed sown 4 yrs post-fire survived one year. High rates of mycorrhizal colonization were found on white spruce seedlings planted 1-year post-fire, including early and late stage fungal species. Microsite characteristics were only weakly correlated with mycorrhizal fungal communities. We propose that immediate post-fire recruitment of white spruce is a key process in mixedwood boreal succession.
  • Purdy, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 ORCID ID:E-mail:
  • Macdonald, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 ORCID ID:E-mail: ellen.macdonald@ualberta.ca (email)
  • Dale, Dale, Dept. of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 ORCID ID:E-mail:
article id 635, category Research article
Manfred J. Lexer, Karl Hönninger, Helfried Scheifinger, Christoph Matulla, Nikolaus Groll, Helga Kromp-Kolb. (2000). The sensitivity of central European mountain forests to scenarios of climatic change: methodological frame for a large-scale risk assessment. Silva Fennica vol. 34 no. 2 article id 635. https://doi.org/10.14214/sf.635
The methodological framework of a large-scale risk assessment for Austrian forests under scenarios of climatic change is presented. A recently developed 3D-patch model is initialized with ground-true soil and vegetation data from sample plots of the Austrian Forest Inventory (AFI). Temperature and precipitation data of the current climate are interpolated from a network of more than 600 weather stations to the sample plots of the AFI. Vegetation development is simulated under current climate (‘control run’) and under climate change scenarios starting from today's forest composition and structure. Similarity of species composition and accumulated biomass between these two runs at various points in time were used as assessment criteria. An additive preference function which is based on Saaty’s AHP is employed to synthesize these criteria to an overall index of the adaptation potential of current forests to a changing climate. The presented methodology is demonstrated for a small sample from the Austrian Forest Inventory. The forest model successfully simulated equilibrium species composition under current climatic conditions spatially explicit in a heterogenous landscape based on ground-true data. At none of the simulated sites an abrupt forest dieback did occur due to climate change impacts. However, substantial changes occured with regard to species composition of the potential natural vegetation (PNV).
  • Lexer, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria ORCID ID:E-mail: lexer@edv1.boku.ac.at (email)
  • Hönninger, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria ORCID ID:E-mail:
  • Scheifinger, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria ORCID ID:E-mail:
  • Matulla, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria ORCID ID:E-mail:
  • Groll, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria ORCID ID:E-mail:
  • Kromp-Kolb, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria ORCID ID:E-mail:

Category: Review article

article id 10172, category Review article
Ulf Sikström, Karin Hjelm, Kjersti Holt Hanssen, Timo Saksa, Kristina Wallertz. (2020). Influence of mechanical site preparation on regeneration success of planted conifers in clearcuts in Fennoscandia – a review. Silva Fennica vol. 54 no. 2 article id 10172. https://doi.org/10.14214/sf.10172
Highlights: Mechanical site preparation (MSP) increases seedling survival rates by 15–20%; Survival rates of 80–90% ca. 10 years after MSP and planting conifers are possible; MSP can increase tree height 10–15 years after planting by 10–25%; The increase in growth rate associated with MSP may be temporary, but the height enhancement probably persists.

In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.

  • Sikström, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: ulf.sikstrom@skogforsk.se
  • Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden ORCID ID:E-mail: karin.hjelm@skogforsk.se (email)
  • Holt Hanssen, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: kjersti.hanssen@nibio.no
  • Saksa, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: timo.saksa@luke.fi
  • Wallertz, Swedish University of Agricultural Sciences (SLU), Asa Forest Research Station, SE-360 30 Lammhult, Sweden ORCID ID:E-mail: kristina.wallertz@slu.se
article id 446, category Review article
Guntis Brumelis, Bengt Gunnar Jonsson, Jari Kouki, Timo Kuuluvainen, Ekaterina Shorohova. (2011). Forest naturalness in northern Europe: perspectives on processes, structures and species diversity. Silva Fennica vol. 45 no. 5 article id 446. https://doi.org/10.14214/sf.446
Saving the remaining natural forests in northern Europe has been one of the main goals to halt the ongoing decline of forest biodiversity. To facilitate the recognition, mapping and efficient conservation of natural forests, there is an urgent need for a general formulation, based on ecological patterns and processes, of the concept of “forest naturalness”. However, complexity, structural idiosyncracy and dynamical features of unmanaged forest ecosystems at various spatio-temporal scales pose major challenges for such a formulation. The definitions hitherto used for the concept of forest naturalness can be fruitfully grouped into three dimensions: 1) structure-based concepts of natural forest, 2) species-based concepts of natural forest and 3) process-based concepts of natural forest. We propose that explicit and simultaneous consideration of all these three dimensions of naturalness can better cope with the natural variability of forest states and also aid in developing strategies for forest conservation and management in different situations. To become operational, criteria and indicators of forest naturalness need to integrate the three dimensions by combining species (e.g. red-listed-, indicator- and umbrella species) with stand and landscape level structural features that are indicative of disturbance and succession processes.
  • Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga, LV-1586, Latvia; ORCID ID:E-mail: guntis.brumelis@lu.lv (email)
  • Jonsson, Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden ORCID ID:E-mail:
  • Kouki, School of Forest Sciences, University of Eastern Finland, Joensuu, Joensuu ORCID ID:E-mail:
  • Kuuluvainen, Department of Forest Sciences, University of Helsinki, Finland ORCID ID:E-mail:
  • Shorohova, Saint-Petersburg State Forest Academy, Saint-Petersburg, Russia & Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland ORCID ID:E-mail:
article id 73, category Review article
Timo Kuuluvainen, Tuomas Aakala. (2011). Natural forest dynamics in boreal Fennoscandia: a review and classification. Silva Fennica vol. 45 no. 5 article id 73. https://doi.org/10.14214/sf.73
The aim here was to review and summarize the findings of scientific studies concerning the types of forest dynamics which occur in natural forests (i.e. forests with negligible human impact) of boreal Fennoscandia. We conducted a systematic search for relevant studies from selected reference databases, using search terms describing the location, structure and processes, and degree of naturalness of the forest. The studies resulting from these searches were supplemented with other known works that were not indexed in the databases. This procedure yielded a total of 43 studies. The studies were grouped into four types of forest dynamics according to the information presented on the characteristics of the native disturbance-succession cycle: 1) even-aged stand dynamics driven by stand-replacing disturbances, 2) cohort dynamics driven by partial disturbances, 3) patch dynamics driven by tree mortality at intermediate scales (> 200 m2) and 4) gap dynamics driven by tree mortality at fine scales (< 200 m2). All four dynamic types were reported from both spruce and pine dominated forests, but their commonness differed. Gap dynamics was most commonly reported in spruce forests, and cohort dynamics in pine forests. The studies reviewed provide the best obtainable overall picture of scientific findings concerning the characteristics and variability of the unmanaged boreal forest dynamics in Fennoscandia. The results demonstrate that the unmanaged Fennoscandian forests are characterized by more diverse and complex dynamics than has traditionally been acknowledged.
  • Kuuluvainen, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: timo.kuuluvainen@helsinki.fi (email)
  • Aakala, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail:
article id 553, category Review article
Yves Bergeron, Alain Leduc, Brian D. Harvey, Sylvie Gauthier. (2002). Natural fire regime: a guide for sustainable management of the Canadian boreal forest. Silva Fennica vol. 36 no. 1 article id 553. https://doi.org/10.14214/sf.553
The combination of certain features of fire disturbance, notably fire frequency, size and severity, may be used to characterize the disturbance regime in any region of the boreal forest. As some consequences of fire resemble the effects of industrial forest harvesting, conventional forest management is often considered as a disturbance that has effects similar to those of natural disturbances. Although the analogy between forest management and fire disturbance in boreal ecosystems has some merit, it is important to recognise that it also has its limitations. Short fire cycles generally described for boreal ecosystems do not appear to be universal; rather, important spatial and temporal variations have been observed in Canada. These variations in the fire cycle have an important influence on forest composition and structure at the landscape and regional levels. Size and severity of fires also show a large range of variability. In regions where the natural matrix of the boreal forest remains relatively intact, maintenance of this natural variability should be targeted by forest managers concerned with biodiversity conservation. Current forest management tends to reduce this variability: for example, fully regulated, even-aged management will tend to truncate the natural forest age distribution and eliminate over-mature and old-growth forests from the landscape. We suggest that the development of strategic-level forest management planning approaches and silvicultural techniques designed to maintain a spectrum of forest compositions and structures at different scales in the landscape is one avenue to maintain this variability. Although we use the boreal forest of Quebec for our examples, it is possible to apply the approach to those portions of the boreal forest where the fire regime favours the development of even-aged stands in burns.
  • Bergeron, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 ORCID ID:E-mail: bergeron.yves@uqam.ca (email)
  • Leduc, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 ORCID ID:E-mail:
  • Harvey, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 ORCID ID:E-mail:
  • Gauthier, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 ORCID ID:E-mail:

Category: Research note

article id 10009, category Research note
Jānis Donis, Māra Kitenberga, Guntars Šņepsts, Edgars Dubrovskis, Āris Jansons. (2018). Factors affecting windstorm damage at the stand level in hemiboreal forests in Latvia: case study of 2005 winter storm. Silva Fennica vol. 52 no. 4 article id 10009. https://doi.org/10.14214/sf.10009
Highlights: In hemiboreal forests in Latvia, dominant tree species, admixture of spruce in canopy-layer, mean height, timing of thinnings, upwind forest edges and wind gusts had significant effect on windstorm damage occurrence at stand-level; Stands on peat soils were more damaged than stands on mineral soils; Tree species composition of canopy-layer was not statistically significant in the model.

In managed European hemiboreal forests, windstorms have a notable ecological and socio-economic impact. In this study, stand properties affecting windstorm damage occurrence at the stand-level were assessed using a Generalized Linear Mixed model. After 2005 windstorm, 5959 stands dominated by birch (Betula spp.), Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.), with mean height > 10 m were inventoried. Windstorm damage was positively associated with spruce and pine-dominated stands, increasing mean height, fresh forest edges, decreasing time since the last thinning and stronger wind gusts. Tree species composition – mixed or monodominant – was not statistically significant in the model; while, the admixture of spruce in the canopy layer was positively associated with higher windstorm damage. Stands on peat soils were more damaged than stands on mineral soils. Birch stands were more damaged than pine stands. This information could be used in forest management planning, selection of silvicultural treatments to increase forest resilience to natural disturbances.

  • Donis, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 ORCID ID:E-mail: janis.donis@silava.lv (email)
  • Kitenberga, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 ORCID ID:E-mail: mara.kitenberga@gmail.com
  • Šņepsts, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 ORCID ID:E-mail: guntars.snepsts@silava.lv
  • Dubrovskis, Latvia University of Life Sciences and Technologies, Liela iela 2, Jelgava, Latvia, LV-3001 ORCID ID:E-mail: edgars.dubrovskis@llu.lv
  • Jansons, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 ORCID ID:E-mail: aris.jansons@silava.lv

Category: Discussion article

article id 270, category Discussion article
Seppo Rouvinen, Jari Kouki. (2008). The natural northern European boreal forests: unifying the concepts, terminologies, and their application. Silva Fennica vol. 42 no. 1 article id 270. https://doi.org/10.14214/sf.270
Recent emphasis on conserving the biodiversity has stressed the value of natural ecosystems in saving the species from extinction. In the Fennoscandian region the conifer-dominated boreal forests form the largest single ecosystem. The forests have been under varying intensity of human influence for decades or centuries. Recent attempts have tried to seek the last remaining natural forests to be included in the protection programmes. However, due to long and widespread human influence, finding and defining the natural forests has proven to be extremely difficult, not only because they are so rare but also because the concept of natural forest is vague. These difficulties are partly seen through the diverse terminology used. We first review the varying terminology as seen in recent studies. Secondly, we propose the basis for defining the natural forest and show some intriguing and challenging difficulties are involved in the concept. These difficulties are at least partly related to inherent strong and long-term dynamic component in boreal forest ecosystems that is manifested over several temporal and spatial scales. Finally, we outline a more general terminology with associated indicators and measurements that might be used in the classification and terminology. Conceptual clarification is necessary, for example, to compile ecologically justified and representative global, national and regional forest statistics. Many currently applied definitions of “forest” and “natural” that are applied in the context of forest statistics overlook ecologically important components of natural forests, and thus provide quite misleading or inadequate data of existing diversity patterns in these ecosystems.
  • Rouvinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Kouki, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: jari.kouki@joensuu.fi (email)
article id 270, category Discussion article
Seppo Rouvinen, Jari Kouki. (2008). The natural northern European boreal forests: unifying the concepts, terminologies, and their application. Silva Fennica vol. 42 no. 1 article id 270. https://doi.org/10.14214/sf.270
Recent emphasis on conserving the biodiversity has stressed the value of natural ecosystems in saving the species from extinction. In the Fennoscandian region the conifer-dominated boreal forests form the largest single ecosystem. The forests have been under varying intensity of human influence for decades or centuries. Recent attempts have tried to seek the last remaining natural forests to be included in the protection programmes. However, due to long and widespread human influence, finding and defining the natural forests has proven to be extremely difficult, not only because they are so rare but also because the concept of natural forest is vague. These difficulties are partly seen through the diverse terminology used. We first review the varying terminology as seen in recent studies. Secondly, we propose the basis for defining the natural forest and show some intriguing and challenging difficulties are involved in the concept. These difficulties are at least partly related to inherent strong and long-term dynamic component in boreal forest ecosystems that is manifested over several temporal and spatial scales. Finally, we outline a more general terminology with associated indicators and measurements that might be used in the classification and terminology. Conceptual clarification is necessary, for example, to compile ecologically justified and representative global, national and regional forest statistics. Many currently applied definitions of “forest” and “natural” that are applied in the context of forest statistics overlook ecologically important components of natural forests, and thus provide quite misleading or inadequate data of existing diversity patterns in these ecosystems.
  • Rouvinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Kouki, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: jari.kouki@joensuu.fi (email)
article id 571, category Discussion article
S. C. DeLong. (2002). Using nature’s template to best advantage in the Canadian boreal forest. Silva Fennica vol. 36 no. 1 article id 571. https://doi.org/10.14214/sf.571
  • DeLong, Ministry of Forests, 1011 4th Ave, Prince George, BC, Canada V2L 3H9 ORCID ID:E-mail: craig.delong@gems1.gov.bc.ca (email)

Category: Article

article id 7170, category Article
Yrjö Ilvessalo. (1967). Luonnonnormaalien metsiköiden kehityksestä Kainuussa ja sen lähiympäristössä. Acta Forestalia Fennica vol. 81 no. 5 article id 7170. https://doi.org/10.14214/aff.7170
English title: The development of natural normal forest stands in southeastern Northern Finland.

Examination of stands developed under natural conditions can be used to provide basis for comparison for study of the development and yield of stands treated with intermediate fellings. In Finland, the first investigation and the yield and the structure of natural normal stands were published in 1920. This investigation on development and yield of the natural forests of Kainuu in southeastern Northern Finland is based on 92 sample plots on three forest types; Empetrum-Vaccinium type (EVT), Empetrum-Calluna type (ECT) and Vaccinium-Myrtillus type (VMT).

The Scots pine (Pinus sylvestris L.) sample plots represented variation of age classes for construction of mean development series. The Norway spruce (Picea abies (L.) H. Karst.) of the region are so old that development series could be obtained only for dominant trees based on stem analysis.

The average development of Scots pine stand on EMT type within the region is on average more rapid and the yield in cubic volume quantitatively larger and structurally better than that on ECT type. Self-thinning during the early decades of EVT is slower. The pine stands are denser in the age of 70 in Kainuu compared to Central Northern Finland, but the development and yield are similar.

The development, yield and structure of natural Norway spruce stand on VMT proved considerably inferior to the average level of pine stands on EVT, and to a major part on ECT. The mixed pines on spruce sample plots have developed better than spruces of equal age. Spruce stands on VMT in the area developed markedly better than Geranium-Dryopteris-Myrtillus (GDMT) in Central Northern Finland.

It seems that a spruce stand seems to require more fertile site type in north than in the southern part of Finland. These fertile types are relative rare in the north. In the region, the best results are received with pine. As a rule, also the yield of birch (Betula sp.) is poor in the region.

The PDF includes a summary in English.

  • Ilvessalo, ORCID ID:E-mail:
article id 7170, category Article
Yrjö Ilvessalo. (1967). Luonnonnormaalien metsiköiden kehityksestä Kainuussa ja sen lähiympäristössä. Acta Forestalia Fennica vol. 81 no. 5 article id 7170. https://doi.org/10.14214/aff.7170
English title: The development of natural normal forest stands in southeastern Northern Finland.

Examination of stands developed under natural conditions can be used to provide basis for comparison for study of the development and yield of stands treated with intermediate fellings. In Finland, the first investigation and the yield and the structure of natural normal stands were published in 1920. This investigation on development and yield of the natural forests of Kainuu in southeastern Northern Finland is based on 92 sample plots on three forest types; Empetrum-Vaccinium type (EVT), Empetrum-Calluna type (ECT) and Vaccinium-Myrtillus type (VMT).

The Scots pine (Pinus sylvestris L.) sample plots represented variation of age classes for construction of mean development series. The Norway spruce (Picea abies (L.) H. Karst.) of the region are so old that development series could be obtained only for dominant trees based on stem analysis.

The average development of Scots pine stand on EMT type within the region is on average more rapid and the yield in cubic volume quantitatively larger and structurally better than that on ECT type. Self-thinning during the early decades of EVT is slower. The pine stands are denser in the age of 70 in Kainuu compared to Central Northern Finland, but the development and yield are similar.

The development, yield and structure of natural Norway spruce stand on VMT proved considerably inferior to the average level of pine stands on EVT, and to a major part on ECT. The mixed pines on spruce sample plots have developed better than spruces of equal age. Spruce stands on VMT in the area developed markedly better than Geranium-Dryopteris-Myrtillus (GDMT) in Central Northern Finland.

It seems that a spruce stand seems to require more fertile site type in north than in the southern part of Finland. These fertile types are relative rare in the north. In the region, the best results are received with pine. As a rule, also the yield of birch (Betula sp.) is poor in the region.

The PDF includes a summary in English.

  • Ilvessalo, ORCID ID:E-mail:
article id 7129, category Article
Erkki K. Kalela. (1961). Über die natürliche Bewaldung der Kulturböden im sog. Porkkala-Pachtgebiet. Acta Forestalia Fennica vol. 74 no. 2 article id 7129. https://doi.org/10.14214/aff.7129
English title: Natural regeneration of agricultural lands in so-called Porkkala-area of leased land.

The size of the field and the ditching on it as well as the condition of the field at the time of the surrender of Porkkala area (from Finland to Russia) play an important role on how far the natural regeneration of the fields has progressed.

Larger open fields have naturally regenerated only on sides where the surrounding forest can spread the seeds or the thicket of saplings has reached, whereas small parcels of fields have normally been fully forested. Most important species have been e.g. silver birch and pubescent birch, grey and common alders and European aspen as well as pine and spruce. The broad leaved species are dominant.     

The PDF contains a summary in Finnish.

 

  • Kalela, ORCID ID:E-mail:
article id 7478, category Article
Paavo Yli-Vakkuri. (1958). Tutkimuksia ojitettujen turvemaiden kulotuksesta. Acta Forestalia Fennica vol. 67 no. 4 article id 7478. https://doi.org/10.14214/aff.7478
English title: Studies on prescribed burning of drained peatlands.

Prescribed burning has been used to treat the mineral soil sites, but the method has been little used in drained peatlands. The course and methods of prescribed burning in drained peatlands, and the effect of burning on sprouting of broadleaved trees, growth of ground vegetation and regeneration of Scots pine (Pinus sylvestris L.) by sowing was studied in drained pine bogs in Southern Finland. The top layer of the peat was mostly Sphagnum peat. The material included a prescribed burned 12 ha drained peatland area in Tuomarniemi district, in addition to which ten previously burned areas were investigated.

The burning had succeeded mostly well, but also unsuccessfully burned sites were observed. Estinguishing of the fire was easy, and no peat fires occurred. The fire burned only the logging residue, ground vegetation and the dry top layer of the peat. The roots of brushwood and grasses survived in the peat that insulated the top layer from the heat. For instance, the abundance of cloudberry (Rubus chamaemorus L.) increased after the fire. Similarly, burning did not affect sprouting of the stumps of downy birch (Betula pubescens Ehrh.). It cannot thus be used as a method to restrict the growth of coppice in regenerated areas. The seeds of Scots pine germinated well on the burned surface. 46% of the seeds developed to seedlings on sphagnum-shrub vegetation and 16% in feathermoss-shrub vegetation.

The PDF includes a summary in German.

  • Yli-Vakkuri, ORCID ID:E-mail:
article id 7472, category Article
Jaakko Lehto. (1956). Tutkimuksia männyn luontaisesta uudistumisesta Etelä-Suomen kangasmailla. Acta Forestalia Fennica vol. 66 no. 2 article id 7472. https://doi.org/10.14214/aff.7472
English title: Studies on the natural regeneration of Scots pine on the upland soils of Southern Finland.

Natural regeneration of Scots pine (Pinus sylvestris L.) by leaving a seed tree stand on a cutting area has long been the most popular regeneration method in Finland. Results of the method have, however, been unsatisfactory. The aim of the investigation was to study the basic problems of natural regeneration of Scots pine. Regeneration success was studied in 144 sample plots in pine stands at different stages of regeneration in Southern Finland. In addition, the data included information of 42 previously investigated areas.

According to the results, Scots pine can be successfully regenerated naturally on sandy and gravelly soils in Southern Finland. Preparing the ground surface by breaking or burning considerably facilitates the establishment of a seedling stand. The number of seedlings was considerably lower in the ground vegetation than in the mineral soil. Considering growth of the seedlings, root competition of the mother trees was heavy in dense stands, but insignificant in thin stands. The stand density did not affect germination of the seeds. In regeneration areas proper, where the density of mother trees usually is under 50 per hectare, there was in average 4,700 seedlings per hectare in Calluna type forests and 5,200 in Vaccinium type forests.

The PDF includes a summary in English.

  • Lehto, ORCID ID:E-mail:
article id 7440, category Article
Erkki K. Kalela. (1954). Mäntysiemenpuiden ja -puustojen juurisuhteista. Acta Forestalia Fennica vol. 61 no. 28 article id 7440. https://doi.org/10.14214/aff.7440
English title: Root systems of Scots pine seed trees and stands.

Root systems of a Scots pine (Pinus sylvestris L.) stands of seed trees on a Vaccinium sites in Southern Finland were studied by taking soil samples around the seed trees. The results show that root system of an old Scots pine spreads relatively evenly around the tree up to at least 10 meters from the stem. The densest part of the root system is near the stem, which part is often acentric. This is probably due to root competition in the early stages of growth of the tree.

Root systems of the seed trees affect stocking of the site with seedlings and the growth of the seedlings. The root competition can cause, for instance, uneven grouping of the seedlings. It seems that the largest trees of a stand have the most even root system. It is therefore recommended to choose the strongest trees of the stand as seed trees, to ensure even distribution of seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

  • Kalela, ORCID ID:E-mail:
article id 7439, category Article
Leo Heikurainen. (1954). Rämemänniköiden uudistamisesta paljaaksihakkausta käyttäen. Acta Forestalia Fennica vol. 61 no. 27 article id 7439. https://doi.org/10.14214/aff.7439
English title: Regeneration of Scots pine stands of pine swamps through clear cutting.

Pine swamps are easily regenerated by natural regeneration of Scots pine (Pinus sylvestris L.). Usually seeding felling is used, but also strip system or clear cutting and regeneration along stand edge has been suggested. This article discusses the regeneration by clear cutting and sparing the existing undergrowth. The article focuses on pine swamps to be drained and the ones in natural state.

Pine swamps in natural state usually have plenty of trees of smaller diameter classes, that can be trusted to form the future tree generation after the felling. This shortens the rotation by 20-30 years. The undergrowth has been shown to recover quickly. The method suits for regeneration of drained peatlands but could fit also for regeneration of pine swamps in natural state.

The seedlings in the pine swamps are mainly 1-5 years old, and the stock is changing. It seems that larger trees produce a wider selection of age groups, but the seedlings survive longer under smaller mother trees. Part of the younger generations of seedlings seem to be destroyed when the peatland is drained. Further studies are needed to investigate how the draining and felling are to be performed to spare the young seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

  • Heikurainen, ORCID ID:E-mail:
article id 7402, category Article
Gustaf Sirén. (1950). Alikasvoskuusten biologiaa. Acta Forestalia Fennica vol. 58 no. 2 article id 7402. https://doi.org/10.14214/aff.7402
English title: On the biology of undergrown Norway spruce.

Norway spruce (Picea abies (L.) Karst.) invading sites is common in Finland. The species tends to establish itself as undergrowth, and takes over when it gets space to grow. To determine whether the undergrowth is suitable as the new generation requires knowledge on the biology of spruce undergrowth. One of the issues is determining the age of the stunted trees. In this investigation, 100 undergrown spruce trees, their crown and their root systems were studied. A method was developed to determine the age of the trees.

The root system of all trees in Vaccinium sites and of stunted trees in Myrtillius sites were superficial. The root systems of older spruces were purely of adventitious origin. The longer the period of stunting growth, the younger is the root system. In addition to acropetal and general adventitious ramification there is often adventitious branching of the roots of pathological causes. Mortality among the long roots is frequent.

A stunted tree has not the same ability as a viable tree to make use of already existing branches for building assimilating surface. When comparing trees with equally large assimilating surface, a stunted tree had greater sum of roots compared to a viable tree. The root system of a stunted undergrown spruce was very superficial compared with the other trees.

The PDF includes a summary in English.

  • Sirén, ORCID ID:E-mail:
article id 7294, category Article
Martti Hertz. (1934). Tutkimuksia karjan vaikutuksesta hakkausalojen kasvillisuuteen. Acta Forestalia Fennica vol. 40 no. 17 article id 7294. https://doi.org/10.14214/aff.7294
English title: Studies on influence of grazing on the vegetation of cutting areas.

The aim of the study was to determine the effect of grazing of the cutting areas to the ground vegetation and regeneration of spruce. The cutting areas could be divided into two kinds of areas based on the vegetation. Hillocks were drier and poorer than other parts of the cutting areas. Their vegetation did suffer less from grazing than the other parts of the cutting areas. The shade-loving plant species decreased, but as the poorer sites have less edible plants, cattle caused less damage than in the better sites. The even spaces between the hillocks had both positive and negative changes. Cattle transport seeds, tile and fertilize the soil, promote paludification, and decrease competition by the primary species like large grasses. This is beneficial to new species. Grazing is directed to large grass species like Calamagrostis. Those species that cattle reject, become more abundant. Stamping damages especially shallow rooted species and perennial species, like Norway spruce (Picea abies (L.) H. Karst.). Larger tree seedlings may get injuries in the stem.

The PDF includes a summary in German.

  • Hertz, ORCID ID:E-mail:
article id 7256, category Article
V. Pöntynen. (1929). Tutkimuksia kuusen esiintymisestä alikasvoksina Raja-Karjalan valtionmailla. Acta Forestalia Fennica vol. 35 no. 1 article id 7256. https://doi.org/10.14214/aff.7256
English title: Studies on Norway spruce undergrowth in state forests in Karelia.

The abundance of Norway spruce (Picae abies (L.) H. Karst.) undergrowth is common for the state forests in Karelia near the Russian border, in Finland. In the survey, the occurrence of the undergrowth was studied. The article includes a review on the ownership of the forest, forest soils in the area, and the state of forests in the area. Scots pine (Pinus sylvestris L.) is the dominative species in 67%, Norway spruce in 27% and Betula sp. 6% of the state forests. Only 2% of the forests are 1‒20 years of age. Stands in the age group of 61‒80 years are the most common (25%). Norway spruce undergrowth is most abundant in the municipality of Salmi. The forests are typically moist forest site types or grass-herb site types. If the stands are allowed to develop naturally, even the Vaccinium sites become Norway spruce dominated. Spruce undergrowth is formed seldom under a spruce forest unless the stand is thin or has openings. Because Norway spruce is often rare in the mineral soil sites, the undergrowth is often regenerated from seeds that spread from spruce swamps. Earlier practiced shifting cultivation and its frequent fires prevented regeneration of spruce undergrowth. Similarly, the common felling method used, clear felling in strips, does not promote spruce undergrowth. Consequently, their occurrence is likely to decrease in the future.

The PDF includes a summary in German.

  • Pöntynen, ORCID ID:E-mail:
article id 7250, category Article
K. T. Jutila. (1929). Ihminen luonnon ja luontonsa hyötyeksponentin kohottajana - kulttuuri-ihminen. Acta Forestalia Fennica vol. 34 no. 37 article id 7250. https://doi.org/10.14214/aff.7250
English title: By raising the degree of utilizing his external and internal nature man becomes the cultured person.
English keywords: natural resources; culture

Man’s existence on the earth depends on his ability to make use of the space, time, material and energy provided for him by Nature. The more able a nation is to increase the utilization of these resources, the higher is the culture and the standard of life in the nation.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

  • Jutila, ORCID ID:E-mail:
article id 7245, category Article
Erik Lönnroth. (1929). Theoretisches über den Volumzuwachs und -abgang des Waldbestandes. Acta Forestalia Fennica vol. 34 no. 32 article id 7245. https://doi.org/10.14214/aff.7245
English title: Theoretical observations on volume growth and drain of a forest stand.
Original keywords: Waldzuwachs; Volumabgang; Volumzuwachs

In a natural state growing closed forest the amount of timber grows yearly. However, in the same time the timber volume also decreases when part of the trees die in the competition for light and other growth factors.

There are many interactive functions and characteristic that influence the growth and drain in a stand. These can be illustrated as mathematical models. The article discusses a set of models.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

  • Lönnroth, ORCID ID:E-mail:
article id 7228, category Article
Agnar Barth. (1929). Skjermforyngelsen i produksjonsökonomisk belysning. Acta Forestalia Fennica vol. 34 no. 15 article id 7228. https://doi.org/10.14214/aff.7228
English title: Natural regeneration from the production economic point of view.

Natural regeneration has been studied so far mostly on the perspective of regeneration, while the production capacity of the seed crop stand has been of little interest in the earlier studies. This paper studied volume growth of the seed trees and the economic impact of this regeneration method both in a literature review and measuring sample stands consisting of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) dominated stands and mixed forests in Norway.

It is concluded that in the most cases the seed tree stands give better pulpwood and timber yield than the stands in the average. The reason might be that the elite stems can better use their production capacity, and, thus, reach bigger and more valuable dimensions. Even though the growing stock diminishes in the seeding felling, the growth of the stand does not decrease or decreases only little. At the same time, the quality growth improves. In addition, the new tree regeneration is achieved usually without extra costs, and there is no unproductive time period in the stand.

  • Barth, ORCID ID:E-mail:
article id 7221, category Article
Konrad Rubner. (1929). Die Ziele der mitteleuropäischen Forstwirtschaft. Acta Forestalia Fennica vol. 34 no. 8 article id 7221. https://doi.org/10.14214/aff.7221
English title: Objectives of middle-European forestry.

The article presents middle-European forests and their characteristics, development and use. The main question is whether the current practice of planted coniferous tree forests should be kept or whether more natural mixed forests should be introduced instead. The article discusses the pros and cons of these and the possible felling and management practices.      

 The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

  • Rubner, ORCID ID:E-mail:
article id 7217, category Article
Bunzo Hayata. (1929). Succession in the vegetation of Mt. Fuji. Acta Forestalia Fennica vol. 34 no. 4 article id 7217. https://doi.org/10.14214/aff.7217

­In different altitudes of the Mount Fuji in Japan occur succession of different tree species. For instance, at an altitude of 2,000 meters are pure stands of Tsuga diversifolia (Maxim.), under which is generally found young trees of Abies veitchii (Lindl.), but not of Tsuga. Abies veitchii is in its turn replaced perhaps with Larix sp. The succession of the forests of the volcano have reached maturity, which is not the case in the east–north-east flank of the mountain, where the Hōei eruption destroyed all vegetation in 1707. The vegetation had not revived even by the 1920s. The Hōei eruption site is compared to the much faster return of vegetation in mount Krakatau in the warmer tropical region. The succession of forests in the other parts of the mountain is described in detail. Finally, a succession theory is proposed that is opposed to the natural selection theory. The theory suggests that there is an Innermost Factor that controls the plant succession. According to the theory, every species, every formation, should die its natural death owing to the Innermost Factor.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

  • Hayata, ORCID ID:E-mail:
article id 5602, category Article
Anatoly Pisarenko, Valentin Strakhov. (1996). Development and utilization of Russian forest resources. Silva Fennica vol. 30 no. 2–3 article id 5602. https://doi.org/10.14214/sf.a9247

A presentation based on the historical development of Russia is given in the form of an overview of the development of Russian forest resources, of the wood, non-wood, and biological aspects of the forest ecosystem. The list of non-wood forest resources includes resin, saps, oils, berries, wild nuts, mushrooms, hay harvesting, game animals, etc. The dynamics of the system are presented in the light of the data of the Forest State Account (FSA) of Russia for the period 1956–1993. The most significant changes in the dynamics of Russia's forest resources are related to concentrated, large-scale wood harvesting operations. The dynamics of non-wood resources follow the process of the economic recession in all parts of the forest sector of Russia, the said recession having begun in the mid-1980s. The forests of Russia are considered to be of immense social and cultural value and a globally significant factor contributing to the sustainable development of forest resources.

  • Pisarenko, ORCID ID:E-mail:
  • Strakhov, ORCID ID:E-mail:
article id 5597, category Article
John C. Brissette. (1996). Effects of intensity and frequency of harvesting on abundance, stocking and composition of natural regeneration in the Acadian forest of eastern North America. Silva Fennica vol. 30 no. 2–3 article id 5597. https://doi.org/10.14214/sf.a9242

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m2 ha-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

  • Brissette, ORCID ID:E-mail:
article id 5595, category Article
R.A. Fleming. (1996). A mechanistic perspective of possible influences of climate change on defoliating insects in North America's boreal forests. Silva Fennica vol. 30 no. 2–3 article id 5595. https://doi.org/10.14214/sf.a9240

There is no doubt that tree survival, growth, and reproduction in North America's boreal forests would be directly influenced by the projected changes in climate if they occur. The indirect effects of climate change may be of even greater importance, however, because of their potential for altering the intensity, frequency, and perhaps even the very nature of the disturbance regimes which drive boreal forest dynamics. Insect defoliator populations are one of the dominating disturbance factors in North America's boreal forests and during outbreaks trees are often killed over vast forest areas. If the predicted shifts in climate occur, the damage patterns caused by insects may be considerably changed, particularly those of insects whose temporal and spatial distributions are singularly dependent on climatic factors. The ensuing uncertainties directly affect depletion forecasts, pest hazard rating procedures, and long-term planning for pest control requirements. Because the potential for wildfire often increases in stands after insect attack, uncertainties in future insect damage patterns also lead to uncertainties in fire regimes. In addition, because the rates of processes key to biogeochemical and nutrient recycling are influenced by insect damage, potential changes in damage patterns can indirectly affect ecosystem resilience and the sustainability of the multiple uses of the forest resource.

In this paper, a mechanistic perspective is developed based on available information describing how defoliating forest insects might respond to climate warming. Because of its prevalence and long history of study, the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used for illustrative purposes in developing this perspective. The scenarios that follow outline the potential importance of threshold behaviour, historical conditions, phenological relationships, infrequent but extreme weather, complex feedbacks, and natural selection. The urgency of such considerations is emphasized by reference to research suggesting that climate warming may already be influencing some insect lifecycles.

  • Fleming, ORCID ID:E-mail:
article id 7196, category Article
Erik Lönnroth. (1925). Untersuchungen über die innere Struktur und Entwicklung gleichaltriger naturnormaler Kiefernbestände : basiert auf Material aus der Südhälfte Finnlands. Acta Forestalia Fennica vol. 30 no. 1 article id 7196. https://doi.org/10.14214/aff.7196
English title: Studies on internal structure and development of even aged natural normal pine stands: based on the data from southern part of Finland.

Study is based on the strip-wise survey of forests in southern Finland. From that information the 30 sample plots were chosen, 10 of each of most typical forest site types, MT, VT and CT. The stands are of different ages and development classes, varying from 14 to 159 years.

The article discusses the earlier literature on the factors effecting forest stands and presents the data in detail. The results section is divided into paragraphs on number of stems of the stand, height, crown, breast height diameter, basal area and volume. The statistical numbers are calculated and presented.    

  • Lönnroth, ORCID ID:E-mail:
article id 5573, category Article
Ilkka Vanha-Majamaa, Raili Suominen, Tiina Tonteri, Eeva-Stiina Tuittila. (1996). Seedling establishment after prescribed burning of a clear-cut and a partially cut mesic boreal forest in southern Finland. Silva Fennica vol. 30 no. 1 article id 5573. https://doi.org/10.14214/sf.a9218

The prescribed burning of a 7.3 ha clear-cut and a 1.7 ha partially cut forest (volume 150 m3/ha) was carried out in Evo (61 °12'N, 25°07'E) on 1 June 1992. The forest was a mesic Myrtillus site type forest dominated by Norway spruce (Picea abies (L.) H. Karst.). Practically all the trees and the above-ground parts of the understorey vegetation died in the fire, while the mor layer was thinned by an average of 1.5 cm.

A study was made on the change of germinated seedling population in time and their dependence on environmental factors. Seedlings of Norway spruce, Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), pubescent birch (B. pubescens Ehrh.) and rowan (Sorbus aucuparia L.) were inventoried in 1993 and in 1994 on permanent plots, four times per growing season. Autoregression models were used to compare regeneration of tree species in the burned forest with regeneration in the burnt clear-cut area, and to study the effect of distance from nearest seed source to regeneration.

The average number of seedlings germinating in 1993 was higher than in 1994, probably because of differences between these consecutive years in regard to the amount of seed rain and weather conditions. The number of Norway spruce and rowan seedling was higher inside the forest area than in the clear-cut area. The distance to the bordering forest and to the closest seed tree did not explain the result. It is suggested that the more stable microclimatic conditions under the shade of dead tree promote germination and seedling establishment in the forest area. As rowan is a bird-dispersed species, it is likely that dead trees help the dispersal of rowan seed by providing birds place to sit and defecate. The shade provided by dead trees may influence the further succession of the tree stand and vegetation composition and diversity.

  • Vanha-Majamaa, ORCID ID:E-mail:
  • Suominen, ORCID ID:E-mail:
  • Tonteri, ORCID ID:E-mail:
  • Tuittila, ORCID ID:E-mail:
article id 7195, category Article
Martti Hertz. (1925). Niinipuun uudistumisesta Suomessa. Acta Forestalia Fennica vol. 29 no. 5 article id 7195. https://doi.org/10.14214/aff.7195
English title: Regeneration of small leaved lime in Finland.

The northern range of small leaved lime (Tilia cordata Mill.) in Finland has remained the same since the end of 1800s, but according to the studies of subfossiles of lime found in peatlands, the northern limit has once been higher than at the present. The northernmost natural specimens of the species in Reisjärvi do not produce seed, and are therefore probably a relict. The article includes a review on the distribution of the species in Finland and its capacity to regenerate. The natural regeneration of lime in Finland is at present very rare. The species has lost its ability to sexual reproduction, but reproduces readily vegetatively.

The PDF includes a summary in German.

  • Hertz, ORCID ID:E-mail:
article id 5562, category Article
Janne Uuttera, Matti Maltamo. (1995). Impact of regeneration method on stand structure prior to first thinning. Comparative study North Karelia, Finland vs. Republic of Karelia, Russian Federation. Silva Fennica vol. 29 no. 4 article id 5562. https://doi.org/10.14214/sf.a9213

Comparisons were made between artificially and naturally regenerated stands in the south-eastern part of North Karelia, Finland, and naturally regenerated stands in the western parts of the Republic of Karelia, Russian Federation. The effect of soil fertility and silvicultural operations on the stand structure was also investigated.

The results of the study show clearly that when forests are artificially regenerated the stand structure includes less variation when compared with the stands naturally regenerated. Differences between the regeneration methods are clearer the more fertile the forest site is. Within the regeneration method there is also a clear trend in stand structure, with the variation decreasing the poorer the site. The effect of silvicultural operations, i.e. the cleaning of the sapling stand, has disappeared by the time of first thinning, although it appears to have a permanent effect on the dynamics of the tree species within a stand.

The variation of the stand structure can be regarded as an essential factor for the potential biodiversity of the stand also at its young vegetation succession stage. This capacity for maintaining the forest biodiversity, developed at the young vegetation succession stage, becomes increasingly important in subsequent vegetation succession stages. Natural regeneration provides improved possibilities for the operations preserving forest biodiversity, as it generates more dense stands with a wider variation in stand structure, compared to artificial regeneration.

  • Uuttera, ORCID ID:E-mail:
  • Maltamo, ORCID ID:E-mail:
article id 5557, category Article
Klaus Silfverberg. (1995). Forest regeneration on nutrient-poor peatlands: Effects of fertilization, mounding and sowing. Silva Fennica vol. 29 no. 3 article id 5557. https://doi.org/10.14214/sf.a9208

The effects of wood ash and PK fertilization on natural regeneration and sowing of Scots pine (Pinus sylvestris L.) were studied in field experiments on nitrogen-poor (Ntot 0.87–1.26%) peat substrates. The study material was derived from three drained, nutrient-poor pine mires (64°52’ N, 25°08’ E) at Muhos, near Oulu, Finland. The experimental fields were laid out in 1985 as a split-split-plot design including the following treatments; mounding, natural regeneration and sowing and fertilization; PK (400 kg ha-1) and wood ash (5,000 kg ha-1). The seedlings were inventoried in circles in July–August 1991.

Changes in the vegetation were small and there were no statistical differences due to the fertilization treatments in the ground vegetation. PK or ash fertilization did not cause vegetation changes harmful to Scots pine regeneration on nitrogen-poor peatlands. Both sowing and fertilization significantly increased the number of pine seedlings, but not their height. Wood ash increased seedling number more than PK fertilizer. The number of seedlings varied from 7,963 (control) to 42,781 ha-1 (mounding + sowing + ash). The seedling number was adequate for successful regeneration even on non-mounded, non-fertilized naturally regenerated plots.

The number of birch seedlings varied more than that of pine (370–25,927 ha-1). Mounding especially increased the number of birches. The difference between PK fertiliser and ash was less pronounced than that for pine. In addition, to the field studies the effects of ash and PK fertilizer on the germination of Scots pine seeds was studied in a greenhouse experiment. Soaking in ash solutions strongly reduced seed germination, while the PK solution was less harmful.

  • Silfverberg, ORCID ID:E-mail:
article id 5413, category Article
Eljas Pohtila. (1990). Metsän uudistuminen Kivalon vanhoilla kaistalehakkuualoilla. Silva Fennica vol. 24 no. 1 article id 5413. https://doi.org/10.14214/sf.a15565
English title: Forest regeneration of old strip cutting areas in Kivalo.

The results of regenerating 54 and 36–38-year old strip cuttings were surveyed in the Kivalo Research Forest (N 66°20’, E 26°40’). 15 measurement plots were placed on each strip. The most common forest type was Hylocomnium-Myrtillus type. Regeneration of the strips proved to be slow. Most of the spruces growing on the strips probably originated from the time before the cutting. The average number of stems was 1,155 per ha, of which one third consisted of broadleaved trees. The average volume increment of stem wood after cutting had been about 1 m3/ha/yr, but it was increasing at the time of the inventory. Both the reforestation of the strips and the development of the emergent stands were dependent on elevation and site fertility. Site fertility was indicated by the abundance of Vaccinium myrtillus.

The PDF includes an abstract in English.

  • Pohtila, ORCID ID:E-mail:
article id 5404, category Article
Pentti Alho. (1990). Suomen metsittyminen jääkauden jälkeen. Silva Fennica vol. 24 no. 1 article id 5404. https://doi.org/10.14214/sf.a15556
English title: The history of forests in Finland after the last ice age.

Based on literature this paper describes the natural afforestation of Finland that took place after the last ice age and the changes which have taken place during the last 10,000 years. The origin and development of the vegetation and trees are related to the changes in the edaphic and climatic factors. The first tree species to arrive in Finland were the primary colonizing species, birch and Scots pine. The appearance of Norway spruce dates back to about 5000 B.P. There have been great changes in the species composition of Finnish forests during the last several thousands of years but some 2,000–3,000 years ago the various species reached their present balance. The epoch of naural forests, which had lasted some 9,500 years, came to a conclusion, however, when man started to have a marked effect on the forest’s development 300–400 years ago.

The PDF includes an abstract in English.

  • Alho, ORCID ID:E-mail:
article id 5404, category Article
Pentti Alho. (1990). Suomen metsittyminen jääkauden jälkeen. Silva Fennica vol. 24 no. 1 article id 5404. https://doi.org/10.14214/sf.a15556
English title: The history of forests in Finland after the last ice age.

Based on literature this paper describes the natural afforestation of Finland that took place after the last ice age and the changes which have taken place during the last 10,000 years. The origin and development of the vegetation and trees are related to the changes in the edaphic and climatic factors. The first tree species to arrive in Finland were the primary colonizing species, birch and Scots pine. The appearance of Norway spruce dates back to about 5000 B.P. There have been great changes in the species composition of Finnish forests during the last several thousands of years but some 2,000–3,000 years ago the various species reached their present balance. The epoch of naural forests, which had lasted some 9,500 years, came to a conclusion, however, when man started to have a marked effect on the forest’s development 300–400 years ago.

The PDF includes an abstract in English.

  • Alho, ORCID ID:E-mail:
article id 7103, category Article
J. P. Norrlin. (1923). Flora Kareliae onegensis. I. Über die Vegetation von Onega-Karelien und die naturgeschichtliche Grenze Finnlands sowie Skandinaviens im Osten. Acta Forestalia Fennica vol. 23 no. 4 article id 7103. https://doi.org/10.14214/aff.7103
English title: Flora in area of Ääninen (Onega)-lake in Russian Karelia – Vegetation of Onega Karelia area and the natural historical border of Scandinavia and Finland in East.

The article begins on the page 27/122 of the PDF file.

The first part of the text deals with a general presentation of the geographical, biological and cultural conditions of the studied areas. The second part presents the characteristics of vegetation classified according the forest types, with lists of species. Forested areas, open lands and swampy areas are dealt with separately. The Saoneshje peninsula is presented separately.

The third part of the text discusses the similarities of the natural conditions between studied area and respective part of Finland. The vegetation and amount of species is clearly more diverse in studied area than in parts of middle-Finland. The study shows that in respect to vegetation Onega-Karelia cannot be seen as a part of the same region than Finland.  

  • Norrlin, ORCID ID:E-mail:
article id 5379, category Article
Timo Kuuluvainen, Timo Pukkala. (1989). Effect of Scots pine seed trees on the density of ground vegetation and tree seedlings. Silva Fennica vol. 23 no. 2 article id 5379. https://doi.org/10.14214/sf.a15536

The study uses the methodology of ecological field theory to model the effect of Scots pine (Pinus sylvestris L.) seed trees on the density of tree seedlings and other plants in the field layer. The seed trees had a clear effect on the expected value of the amount and distribution of the ground vegetation. The vicinity of seed trees had an adverse effect on the growth of grasses, herbs and seedlings, while mosses were most abundant near the trees. Models based on the ecological field approach were derived to describe the effect of seed trees on the ground vegetation.

The PDF includes an abstract in Finnish.

  • Kuuluvainen, ORCID ID:E-mail:
  • Pukkala, ORCID ID:E-mail:
article id 5327, category Article
Yrjö Sepänmaa. (1987). Metsäestetiikka ja metsän estetiikka. Silva Fennica vol. 21 no. 4 article id 5327. https://doi.org/10.14214/sf.a15484
English title: Forstästhetik and forest aesthetics.

Forstästhetik is a programme for forest management, resembling an art manifesto. Forest managers are programme executors. Forest aesthetics is forest investigation from the point of view of beauty. In the case of managed forests, it is possible to ask, what is the manager’s programme and his skill to achieve personal solutions. In forests, the functioning and sustainability of the ecosystem are basic principles affecting all other values. On this basis it is possible to evaluate the competence of taste systems and the logic of their application.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in English.

  • Sepänmaa, ORCID ID:E-mail:
article id 5311, category Article
Timo Pukkala. (1987). Kuusen ja männyn siemensadon ennustemalli. Silva Fennica vol. 21 no. 2 article id 5311. https://doi.org/10.14214/sf.a15468
English title: Model for predicting the seed crop of Picea abies and Pinus sylvestris.

The seed crop of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) is predicted with the help of mean monthly temperatures during May–August one and two years before the flowering year. The prediction models were made separately for Lapland and for the rest of Finland. The models are based on 10-year periods of seed crop measurements and climatic data. The total number of time series was 59.

In Lapland, Norway spruce flowered abundantly and produced an abundant seed crop after warm July–August and two years after cool July–August. In other parts of Finland, warm June and July produced a good flowering year, especially if these months were cool two years before the flowering year.

In Lapland, Scots pine flowered abundantly if the whole previous growing season was warm. Elsewhere in Finland, a cool June preceded prolific flowering in the coming year if the rest of the growing season was considerably warmer than the average.

The prediction models explained 37–49 % of the variation in the size of the seed crop. The occurrence of good and poor seed years was usually predicted correctly. Using the presented models, the prediction of the seed crop is obtainable 1.5 year for Norway spruce and 2.5 year for Scots pine before the year of seed fall.

The PDF includes an abstract in English.

  • Pukkala, ORCID ID:E-mail:
article id 5302, category Article
Seppo Kellomäki, Heikki Hänninen, Taneli Kolström, Ahti Kotisaari, Timo Pukkala. (1987). A tentative model for describing the effects of some regenerative process on the properties of natural seedling stands. Silva Fennica vol. 21 no. 1 article id 5302. https://doi.org/10.14214/sf.a15459

The effect of the size of seed crop, dispersal of seeds and the early development of seedlings on the density and spatial distribution of young Scots pine (Pinus sylvestris L.) stands are evaluated on the basis of theoretical models. The models include (i) number and spatial distribution of parent trees on the regeneration area, (ii) size of annual seed crop, (iii) seed dispersal from a particular parent tree, (iv) germination of the seeds (germination percentage), (v) death of ageing seedlings after the establishment process, and (vi) height growth of the seedlings.

As expected, stand density and spatial distribution varied within a large range in relation to the density of the parent trees and the distance from them. The simulations also showed that natural seedling stands can be expected to be heterogenous due to the geometry of seed dispersal, emphasizing the frequency of young and small trees. The properties of the seedling stands were, however, greatly dependent on the density of the parent trees and the length of the regeneration period.

The PDF includes an abstract in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Hänninen, ORCID ID:E-mail:
  • Kolström, ORCID ID:E-mail:
  • Kotisaari, ORCID ID:E-mail:
  • Pukkala, ORCID ID:E-mail:
article id 5294, category Article
Gordon D. Lewis. (1986). The role of policy in forest resource development. Silva Fennica vol. 20 no. 4 article id 5294. https://doi.org/10.14214/sf.a27750

A nation that wishes to enhance its social and economic well-being through more intensive utilization of its forest resources must develop a rather comprehensive policy statement to ensure that the expanded exploitation does not lead to the destruction of these resources. The policy must specify the goals to be achieved, provide general direction on how these goals can be achieved, and develop a system of checks-and-balances to ensure achievement of the long-term objectives. The policy must consider resource protection, the economic needs at the various levels of government, the social impacts of utilization on ways of life in all areas of the nation, and the infrastructure needed in the short and long terms.

  • Lewis, ORCID ID:E-mail:
article id 5289, category Article
Karl Gustaf Löfgren. (1986). Effects of permanent and non-permanent forest policy means on timber supply. Silva Fennica vol. 20 no. 4 article id 5289. https://doi.org/10.14214/sf.a27745

To conduct an efficient forest policy, both a normative and a positive theory are necessary. In addition, however, the explicit intertemporal considerations in natural resource economics demand that it is made crystal clear which means are permanent and which are non-permanent. The permanent case is far from easy to solve.

That the theoretical problems have practical relevance is shown by Swedish experience. A practical course of action is to weight possible positive effects from a permanent subsidy against possible deleterious outcomes. It is also desirable to avoid jerkiness in forest policy, which is likely to create uncertainty about the permanence of permanent means.

Law may sometimes be more efficient in creating ”credibility” than economic incentives. Regeneration has been mandatory in Sweden since 1903, and nobody refrains from cutting because he believes that regeneration duty will be abolished in some near future.

  • Löfgren, ORCID ID:E-mail:
article id 5218, category Article
Jouni Suoheimo. (1984). Isokorvakärsäkkään aikuisten esiintyminen ja merkitys männyn luontaiselle uudistamiselle Pohjois-Lapissa. Silva Fennica vol. 18 no. 3 article id 5218. https://doi.org/10.14214/sf.a15397
English title: The occurrence of Otiorrhynchus nodosus and its significance for the natural regeneration of Scots pine in Lapland.

The aim of the present study was to survey the occurrence of Otiorrhynchus nodosus Müller weevils and their significance for the natural regeneration of Scots pine (Pinus sylvestris L.). The study was carried out during summer 1982 at Inari in northern Lapland.

There were two sample plots, one situated in a Scots pine seed-tree area and the other, the control sample plot, in an area with a coverage of mountain birch (Betula pubescens subsp. tortuosa, now subsp. czerepanovii). A total of 177 Otiorhynchus weevils were caught. Movement of the weevils reached its climax in July. There were 86% more individuals in the seed-tree area than in the mountain birch area. No damage to the pine germlings or seedlings was not observed, although the situation could be different during the peaks of the veewil populations.

The PDF includes a summary in English.

  • Suoheimo, ORCID ID:E-mail:
article id 5198, category Article
Leo Heikurainen, Jukka Laine, Jarmo Lepola. (1983). Lannoitus- ja sarkaleveyskokeita karujen rämeiden uudistamisessa ja taimikoiden kasvatuksessa. Silva Fennica vol. 17 no. 4 article id 5198. https://doi.org/10.14214/sf.a15181
English title: Fertilization and ditch spacing experiments concerned with regeneration and growth of young Scots pine stands on nutrient poor pine bogs.

The effects of variations in the intensity of drainage and NPK fertilization on the natural regeneration and planting results and the subsequent development of seedling stands under various climatic conditions on drained nutrient poor pine bogs was investigated in a 16-year-old study.

Comparison of height development of Scots pine (Pinus sylvestris L.) stands on drained peatlands to that of pine stands growing in mineral soil sites show that in Southern Finland the most efficient forest improvement measures (10 m ditch spacing and 1,000 kg/ha NPK-fertilization) resulted in growth that corresponds a to a height index of a stand in a Vaccinium type site. Less efficient treatment (30 m ditch spacing and no fertilizer) resulted in growth corresponding the development of young stand in a Calluna type site. In Northern Finland the effect of fertilization on height growth was almost negligible. This is possibly due to a decrease in the nitrogen mobilization from south to north of Finland. Thus, it seems evident that fertilization of young Scots pine stands on nutrient poor drained peatlands can be recommended only in the southern part of the country.

The effect of ditch spacing is same in the whole country. The narrower the spacing the better the height growth. In the south planted stands thrive better than naturally regenerated stands, but the situation is reversed in the north.

The PDF includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
  • Laine, ORCID ID:E-mail:
  • Lepola, ORCID ID:E-mail:
article id 5180, category Article
Mikko Raatikainen, Terttu Raatikainen. (1983). Mustikan sato, poiminta ja markkinointi Pihtiputaalla. Silva Fennica vol. 17 no. 2 article id 5180. https://doi.org/10.14214/sf.a15096
English title: The berry yield, picking and marketing of Vaccinium myrtillus in the municipality of Pihtipudas, northern Central Finland.

A study on the bilberry (Vaccinium myrtillus L.) was made in the municipality of Pihtipudas (about 63° 30’ N, 23° 30’ W) in 1977. Berry yield was surveyed by picking along 17 lines, each 1,000 m long. The lines were chosen randomly and were situated on different vegetation types throughout the municipality. The picking and use of bilberries were studied by an inquiry addressed to a random sample of families living in the area. Marketing of bilberry was investigated by means of report based on purchasing certificates.

The total yield of bilberry in Pihtipudas was 2.4 million kg (21.9 kg/ha). The yield per hectare were best on Vaccinium and Myrtillus type sites, and on swampy heath sites, where the yield was about 27–65 kg/ha, 50% of the yield on the Vaccinium type and 25% of that of Myrtillus type. Only 1.8% of the total bilberry yield was picked from old forests. Women contributed 54, men 34 and children 12% of the volume.

72% of the berries were used for home consumption by the families, 24% were sold and 4% were used for other purposes. The earnings from bilberries for the families that sold berries was in average FIM 178.

The PDF includes a summary in English.

  • Raatikainen, ORCID ID:E-mail:
  • Raatikainen, ORCID ID:E-mail:
article id 7036, category Article
I. Lassila. (1920). Tutkimuksia mäntymetsien synnystä ja kehityksestä pohjoisen napapiirin pohjoispuolella. Acta Forestalia Fennica vol. 14 no. 3 article id 7036. https://doi.org/10.14214/aff.7036
English title: Studies on the regeneration and development of Scots pine forests north of the arctic circle.

The frequency of years when Scots pine (Pinus sylvestris L.) produces cones and seeds affects its reproduction in the north. The study area covered most of the pine lands in Northern Finland. Scots pine seems to be able to produce cones relatively often in the north. The amount of seeds produced in one year was, however, not sufficient to produce a dense seedling stand. Thus, the natural pine stands contain usually trees in different ages-classes, which have germinated in different years. The cone production is highest in 150-170 years old trees. Pine also needs warm summers to produce viable seeds. Brush fires avail the growth of seedlings, because they clear of ground vegetation that hinders germination of seeds. The seedlings need also moisture to survive; good regeneration years have often had rainy summers.

The PDF includes a summary in German.

  • Lassila, ORCID ID:E-mail:
article id 5030, category Article
Camilla Rosengren. (1979). Luonnonkasvillisuus asuntoalueilla. Silva Fennica vol. 13 no. 2 article id 5030. https://doi.org/10.14214/sf.a14886
English title: Natural vegetation within housing areas.

The article describes the results of the studies made in 24 Finnish housing areas. They show that the building density is not as important as the way of building and the site planning, in the view of preserving natural vegetation in the site. Building on slopes was difficult with modern building techniques because of the extensive earthwork required. 

This paper was presented in the ‘Man and the Biosphere’ programme Project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki. 

The PDF includes a summary in English. 

  • Rosengren, ORCID ID:E-mail:
article id 5026, category Article
Alpo Enivaara. (1979). Pyynikin harjumännikön uudistaminen ja elvyttäminen. Silva Fennica vol. 13 no. 2 article id 5026. https://doi.org/10.14214/sf.a14881
English title: Regeneration and improvement of the Scots pine forest of Pyynikki esker in Southern Finland.

Pyynikki is a unique natural park in the centre of the city of Tampere in Southern Finland. Currently, the forest of Pyynikki is losing its vigour because of aging and environmental factors. In 1977 a policy was designed for the regrowth of Scots pine (Pinus sylvestris L.) forest and improvement of the condition of the trees to avoid the situation that the whole pine forest (34 ha) would be regrown at one time. The period of regrowth of pine forest is 60 years. It is accomplished by cutting small openings, on which 4-year old potted pine saplings are planted. Birch will be planted only on two spots. The aim is that the forest scenery will be maintained as undamaged as possible. The condition of the growing forest will be improved by fertilization and thinning.

This paper was presented in the ‘Man and the Biosphere’ programme project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki.

The PDF includes a summary in English.

  • Enivaara, ORCID ID:E-mail:
article id 7024, category Article
August Renvall. (1919). Suojametsäkysymyksestä IV. Poronlaidunnan järjestely suojametsäalueella. Acta Forestalia Fennica vol. 11 no. 4 article id 7024. https://doi.org/10.14214/aff.7024
English title: Protection forests IV.

This fourth part of the six-article series about protection forest in the Northern Finland is a proposal for organizing reindeer grazing to enable scots pine (Pinus sylvestris L.) regeneration near the timber line. Protection forests in the Northern Finland cover third of the natural pastures of reindeer in the area. In these areas reindeer grazing can harm the young pine seedlings. The proposal suggests temporary restrictions in grazing in the coniferous forests. Also, in the northernmost parts of Lapland the pine timberline area would be used only as winter pastures. Regional limits should be set for the number of reindeer. Also the ownership of reindeer herds and herding coopearatives included problematic issues that should be solved.

The article is divided in six parts. A German summary is in a separate PDF.

  • Renvall, ORCID ID:E-mail:
article id 4982, category Article
Olli Järvinen, Kullervo Kuusela, Risto A. Väisänen. (1977). Metsien rakenteen muutoksen vaikutus pesimälinnustoomme viimeisten 30 vuoden aikana. Silva Fennica vol. 11 no. 4 article id 4982. https://doi.org/10.14214/sf.a14836
English title: Effects of modern forestry on the numbers of breeding birds in Finland.

Pair numbers of breeding land birds were estimated from line transects data collected in Finland in 1936–76. The changes observed in the bird populations are in this paper compared with data obtained in the Finnish forest inventories, particularly made in 1951–53 and 1971–76. It is concluded that modern forestry has considerable impact on the breeding bird fauna. In general, more species have increased than decreased due to changes in the forests. Areas affected by forestry are more favourable habitats for many species than natural forests, but, on the other hand, there are certain species which are greatly harmed by the effects of modern forestry.

The PDF includes a summary in English.

  • Järvinen, ORCID ID:E-mail:
  • Kuusela, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
article id 7022, category Article
August Renvall. (1919). Suojametsäkysymyksestä II. Suojametsäjärjestelmän tarkoitusperät ja edellytykset. Acta Forestalia Fennica vol. 11 no. 2-3 article id 7022. https://doi.org/10.14214/aff.7022
English title: Protection forests II.

The second part of the six-article series about protection forest in Northern Finland outlines the principles of protecting Scots pine (Pinus sylvestris L.) timber line. The protected areas should include at least all of the viable pine stands and those birch (Betula sp.) lands that are necessary to safeguard fuel wood supply in the pine forest zone. Outside the actual pine forest zone also those birch stands that are near populated regions should be protected to secure sustainable fuel wood supply. Third, south and down of the pine forest zone should be protected pine forest stands and adjacent open fell areas where forests are especially vulnerable. A new protection forest commission should be established to execute the protection forest legislation.

The article is divided in six parts. The parts II and III of the article series are included in the same PDF. A German summary is in a separate PDF.

  • Renvall, ORCID ID:E-mail:
article id 7013, category Article
Lauri Ilvessalo. (1917). Tutkimuksia mäntymetsien uudistumisvuosista Etelä- ja Keski-Suomessa. Acta Forestalia Fennica vol. 6 no. 2 article id 7013. https://doi.org/10.14214/aff.7013
English title: Studies on the regeneration years of Scots pine forests in Southern and Central Finland.

The success of natural regeneration of Scots pine (Pinus sylvestris L.) is dependent on the amount and quality of seeds produced in each year. While seed production of Scots pine in Northern Finland is well known, there is little information about frequency of good seed years in Southern and Central Finland. The success of regeneration of Scots pine was studied by defining from the growth rings of felled sample trees in which year they started to grow. The aim was to choose sample trees so that they would form a continual series from seedlings to 100 years old trees. In the material there was too little sample trees from certain years. However, within the period of 1827-1910 it could be identified 13 good regeneration years of pine in Southern Finland. According to the study, pine has regenerated very well every 6th year and at least moderately well every 4th year. When compared to the previous studies made in Northern Finland, part of the good regeneration years seems to be same both in Northern and Southern Finland. Regeneration of Scots pine is affected also by the type and condition of the site.

The PDF includes a summary in German.

  • Ilvessalo, ORCID ID:E-mail:
article id 7656, category Article
Kari Leinonen, Matti Leikola, Antti Peltonen, Pentti Räsä­nen. (1989). Kuusen luontainen uudistaminen Pirkka-­Hämeen metsälautakunnassa. Acta Forestalia Fennica no. 209 article id 7656. https://doi.org/10.14214/aff.7656
English title: Natural regeneration of Norway spruce in Pirkka-Häme Forestry Board District, Southern Finland.

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m3/ha (ranging from 80 to 428 m3/ha) and after the cutting 120 m3/ha (39–220 m3/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

  • Leinonen, ORCID ID:E-mail:
  • Leikola, ORCID ID:E-mail:
  • Peltonen, ORCID ID:E-mail:
  • Räsä­nen, ORCID ID:E-mail:
article id 7625, category Article
Antti Turakka, Olavi Luukkanen, Suree Bhumibhamon. (1982). Notes on Pinus kesiya and P. merkusii and their natural regeneration in watershed areas of northern Thailand. Acta Forestalia Fennica no. 178 article id 7625. https://doi.org/10.14214/aff.7625

The aim of the present work was to clarify the structure of selected natural Pinus kesiya Royale ex Gord. And P. merkusii Jungh. et de Vriese stands, with particular attention on the amount and quality of naturally-occurring seedlings and young trees. Furthermore, basic information required in the management of pine stands in watershed areas of northern Thailand was obtained.

Large number of pine seedlings were found in P. kesiyana stands only. Two of the examined four localities where this species occurred also included various intermediary height classes under the mature trees. In dense stands the number of seedlings was generally smaller as compared with lower seed tree densities. Neither one of the two localities where P. Merkusii was investigated indicated sufficient natural regeneration. Young pines (over 5 m height) seemed to survive the frequent ground fires quite well, whereas younger seedlings were destroyed and the ground layer vigour was lowered in these cases.

In situ sowing experiments at the beginning of the dry season indicated a faster development and better survival of emerging P. Kesiya seedlings as compared to P. Merkusii. Soil preparation and exposure to sun decreased the survival of seedlings in both species. Utilization of natural regeneration and direct sowing of pines as a silvicultural method as well as the general significance of the two pine species in the succession of plant communities under the influence of forest fires is also discussed.

The PDF includes a summary in Finnish.

  • Turakka, ORCID ID:E-mail:
  • Luukkanen, ORCID ID:E-mail:
  • Bhumibhamon, ORCID ID:E-mail:
article id 7542, category Article
Yrjö Ilvessalo. (1970). Metsiköiden luontainen kehitys- ja puuntuottokyky Pohjois-Lapin kivennäismailla. Acta Forestalia Fennica no. 108 article id 7542. https://doi.org/10.14214/aff.7542
English title: Natural development and yield capacity of forest stands on mineral soils in Northern Lapland.

The article is fifth part of a series of papers on fully stocked natural normal stands on mineral soils in Finland. This part studies the stands in Northern Lapland, dominated by Scots pine (Pinus sylvestris L.). This investigation was concerned mainly with Scotch pine stands, using Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula sp.) stands for comparison only. 107 sample plots were measured.

The most common forest types in the area are Empetrum-Myrtillus-(Cladina) type, EM(C1), Ericacea-Cladinae type, ErCIT, P-L, and Cladina type, C1T. Stand development is more rapid and wood production greater in EM(C1) type than ErCIT, while the C1T stands are further behind in all respects. The average differences in stand characteristics between forest types are roughly similar, but for cubic volume and total production less, than between the more southerly forest types. Measurements made from increment cores taken at breast height have confirmed that variation of the pine annual ring width has on average been very considerable, in accordance with the climatic, mainly temperature, variations, in the investigation area close to the north pine forest limit.

The few plots from birch and spruce stands measured as samples in the northern Lapland investigation area indicate the generally poor development and wood production of these stands by comparison with pine stands.

The PDF includes a summary in English.

  • Ilvessalo, ORCID ID:E-mail:
article id 7605, category Article
Yrjö Ilvessalo. (1969). Luonnonnormaalien metsiköiden kehityksestä Pohjanmaan kivennäismailla. Acta Forestalia Fennica no. 96 article id 7605. https://doi.org/10.14214/aff.7605
English title: The development of natural normal forest stands on mineral soils in Ostrobothnia in Finland.

The article is third part of a series of papers on fully stocked natural normal stands on mineral soils in Finland. This part studies area between the ca. 62nd and 66nd parallels of the strip of land on the Gulf of Bothnia stretching from the coast to an altitude of 150 m above the sea level. The material consists of 121 sample plots in Scots pine (Pinus sylvestris L.) stands, 36 sample plots in Norway spruce (Picea abies (L.) H. Karst.) and 22 sample plots in birch (Betula sp.) stands.

Since the vegetation gradually changes from south to north, it was considered necessary to separate sub-types (marked s.) for certain southern-central forest types; these are poorer in vegetation but obviously more generally found than the main types. The Myrtillus s. sub-type shows slower development of pine stands than the Myrtillus type. The number of stems on the former is greater, owing to the slow initial development, but the mean diameter and height are smaller than on the latter. The difference in volume and growth increases with age. The slower the rate of self-thinning on the sub-type has the effect that the differences in total production are small.

The Vaccinium sub-type s. (VTs.) is poorer in vegetation than the southern-central type, differs from VT less than was the difference in the MT sub-types. The Empetrum-Vaccinium type (EVT) in general differs considerably from the VT but less from the VTs., in relation to which the difference shows mainly in the volume and total production. The EVT differs from the Calluna type as regards in all stand characteristics.

The results of this study suggest that the s.c. sub-type MT could be placed between the types MT and VT. This has significance especially in forest mensuration. However, in practical forest inventories it would seem possible to combine MT and MTs. to avoid having too many site classes. The types VT and VTs. can generally be considered nearly as one type. Similarly, CT and ECT (Empetrum-Calluna type) may be regarded as one site group. The differences may also partly be due to differences in early treatment of the forests.

The PDF includes a summary in English.

  • Ilvessalo, ORCID ID:E-mail:
article id 4451, category Article
Pekka Urho Sakari Tikka. (1928). Havaintoja kuusen esiintymisestä ja kehityksestä Pohjois-Suomen kuivissa kangasmetsissä. Silva Fennica no. 10 article id 4451. https://doi.org/10.14214/sf.a8399
English title: Observations on Norway spruce growth and development in dry mineral soil sites in Northern Finland.

Norway spruce (Picea abies (L.) H. Karst.) is rarely the dominant species on dry mineral soil sites in Northern Finland. These sites are, in general, too poor and dry for spruce, and suit better for Scots pine (Pinus sylvestris L.). According to the study, the natural regeneration of spruce is in Northern Finland poor. In the sample plots, cones could be found in 35% of spruce trees in the stands in natural state and 46% in the harvested stands. Compared to the spruce areas in Northern Finland, or fresh mineral soil sites in Southern Finland, cone and seed production of Norway spruce was in dry mineral soil sites very low due to scarcity of seed trees and their low cone number. There were few spruce seedlings in the sample plots, but according to the observations, spruce is able to regenerate on lichen and heath covered sites. The seedling growth was, however, poor on dry sites. Spruce seedlings were often found near fallen trees and stumps. The growing trees prevent growth of seedlings of all species. Norway spruce seems, however, to be able to spread also to the poor sites. The success depends on the vegetation and dryness of the site. For instance, spruce can spread to dry mineral soil sites from seed trees of nearby peatlands.

The PDF includes a summary in German.

  • Tikka, ORCID ID:E-mail:
article id 4669, category Article
V. A. Kolehmainen. (1956). Vehkatallinmaa. Silva Fennica no. 90 article id 4669. https://doi.org/10.14214/sf.a9116
English title: Vehkatallinmaa, a successful reforestation area in Central Finland.

In 1933, forest fire caused by locomotive sparkle burned about 600 hectares of forest in a forest district named Vehkatallinmaa, in Central Finland. In 1934–36, the burned area was reforested, using different sowing and planting methods. At the same time, areas with poor runoff were drained. The results from reforestation throughout the area have been good. Also, natural regeneration of coniferous trees, especially Scots pine (Pinus sylvestris L.) has occurred. Even deciduous trees, especially birch (Betula sp.), have regenerated naturally in the area. The forests are an evidence of the adaptability of broadcast sowing on snow crust as a method of reproduction.

The PDF includes a summary in English.

  • Kolehmainen, ORCID ID:E-mail:
article id 4644, category Article
Vilho Antero Kolehmainen. (1955). Havaintoja kulotuksen merkityksestä metsiemme uudistamisessa. Silva Fennica no. 85 article id 4644. https://doi.org/10.14214/sf.a9106
English title: Effect of prescribed burning in the forest regeneration.

Prescribed burning has reported to avail forest regeneration, for instance, by releasing nutrients for the use of seedlings, changing the pH of the soil and decreasing competition of ground vegetation. The aim of the study was to find out if the effects could be verified. Sample plots were measured in the experimental area of Tuomarniemi, in Central Finland, both in previously burned and untreated seedling stands and young forests. The main species in the sample plots was Scots pine (Pinus sylvestris L.).

According to the results, prescribed burning prepares the soil for regeneration. Germination percentage of the seeds is higher on the burned soil. All the species, Scots pine, Norway spruce (Picea abies (L.) Karst.) and birch species (Betula sp.) grow faster. Prescribed burning increases the amount of birch seedlings by improving its regeneration compared to unburned sites. The seed trees survive burning better if they are tall and have short crown, and have thick bark. In general, prescribed burning improves regeneration in seed tree stands.

The article includes a summary in German.

  • Kolehmainen, ORCID ID:E-mail:
article id 4600, category Article
Aarne Nyyssönen. (1950). Vertailevia havaintoja hoidettujen ja luonnontilaisten männiköiden rakenteesta ja kehityksestä. Silva Fennica no. 68 article id 4600. https://doi.org/10.14214/sf.a9091
English title: Comparative study on structure and development of managed and natural Scots pine stands.

The Forest Research Institute of Finland has established permanent sample plots to survey the effect of thinnings on the stands. This study compares the development of tended and natural Scots pine (Pinus sylvestris L.) stands growing on three different forest types: Oxalis-Myrtillus, Vaccinium and Calluna site type. The effect of heavy thinning from below (Oxalis-Myrtillus and Vaccinium site types) and increment felling (Calluna site type) was assessed by dividing the trees of the stands in tree classification classes according to their crown storey and defects.

The results show that thinning from below and increment thinning increase the proportion of trees in the 1st crown storey, which is already large in the natural stands. Also the diameter distribution is more even and the mean diameter higher after the thinnings.

In Scots pine stands in natural state, volume increment per stem is highest in the 1st crown storey and diminishes strongly towards the lower crown storeys. Thinnings increased the increment. The study indicates that many of the objectives of the intermediate cuttings, including promoting the growth of the best trees and improving the quality of the stand, have in general been achieved. Consequently, the thinnings give means to achieve the most valuable yield in the stand.

The article includes a summary in English.

  • Nyyssönen, ORCID ID:E-mail:
article id 4543, category Article
Erkki Laitakari. (1938). Metsän uudistamisesta laihoilla kangasmailla. Silva Fennica no. 46 article id 4543. https://doi.org/10.14214/sf.a13952
English title: Forest regeneration on poor forest sites.

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes forest regeneration on poor forest sites.

  • Laitakari, ORCID ID:E-mail:
article id 4542, category Article
Erkki Laitakari. (1938). Eräitä metsän uudistamisessa huomioon otettavia näkökohtia. Silva Fennica no. 46 article id 4542. https://doi.org/10.14214/sf.a13951
English title: Forest regeneration.

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes factors that should be taken into account in forest regeneration. 

  • Laitakari, ORCID ID:E-mail:
article id 4536, category Article
V. K. Ahola. (1938). Metsän uudistumisen tarkkailusta kovilla metsämailla ja ojitetuilla soilla sekä ojien tarkkailusta. Silva Fennica no. 46 article id 4536. https://doi.org/10.14214/sf.a13945
English title: Inspection of regeneration of forests in mineral soil forests and drained peatlands and checking of ditches.

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes inspection of forest regeneration of mineral soil forest types and drained peatlands, and inspection of ditches. 

  • Ahola, ORCID ID:E-mail:
article id 4530, category Article
O. J. Lukkala. (1938). Ojitettujen soiden metsittämisestä. Silva Fennica no. 46 article id 4530. https://doi.org/10.14214/sf.a13939
English title: Afforestation of drained peatlands.

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes afforestation of drained peatlands. 

  • Lukkala, ORCID ID:E-mail:
article id 4529, category Article
V. T. Aaltonen. (1938). Maa ja metsän uudistuminen. Silva Fennica no. 46 article id 4529. https://doi.org/10.14214/sf.a13938
English title: Forest regeneration and soil.

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes the effect of properties of soil on forest regeneration. 

  • Aaltonen, ORCID ID:E-mail:
article id 4486, category Article
Martti Tertti. (1937). Metsien luontaisen uudistumisen edistämisestä. Silva Fennica no. 39 article id 4486. https://doi.org/10.14214/sf.a13896
English title: Facilitating natural regeneration.

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes natural regeneration in forests and factors affecting the success of regeneration.

  • Tertti, ORCID ID:E-mail:

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